Questions & Answers: "Geometry (Angles, Circles, and 3D Nets)"

Complete guide to "Geometry (Angles, Circles, and 3D Nets)" for Math students. Below you will find important questions and model answers to help you prepare.

91 Questions

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Question 1

1 Mark

All the vertices of a triangle are on the circumference of the circle at equal distances from each other and at a distance of 14 cm. from the centre of the circle. What will be the length of the median of that triangle?

Options

Option A

7 cm.

Option B

14 cm.

Option C is correct

21 cm.

Option D

28 cm.

Question 2

1 Mark

Two triangles are formed by diagonal BD of kite ABCD as shown in the figure. Which test from the following is not applicable for proving these two triangles are congruent?

Diagram for Question 2

Options

Option A

S-A-S

Option B

S-S-S

Option C

A-S-A

Option D is correct

Hypotenuse-side

Question 3

1 Mark

In the adjoining circle with center C, m∠PRS = 55°; then m∠PSQ = ?

Diagram for Question 3

Options

Option A

55°

Option B

40°

Option C

45°

Option D is correct

35°

Question 4

1 Mark

In the adjoining figure, line AB || line CD and m∠RGC = 50°, then find m∠SFA - m∠PEA = ?

Diagram for Question 4

Options

Option A

50°

Option B is correct

80°

Option C

100°

Option D

130°

Question 5

1 Mark

Length of the longest chord of a circle is 7 m. What will be the length of the parallel chord to it, at a distance of 2.1 m.?

Options

Option A

2.8 m.

Option B is correct

5.6 m.

Option C

4.2 m.

Option D

3.5 m.

Question 6

1 Mark

‘Diagonals of the are perpendicular bisectors of each other.’ Choose the correct alternative from given options to complete the above statement. (A) Rectangle (B) Square (C) Rhombus (D) Parallelogram (E) Kite

Options

Option A

Only A and B

Option B is correct

Only B and C

Option C

Only B, C and E

Option D

Only A, B and E

Question 7

1 Mark

Observe the two planes X and Y shown in the diagram and select ‘two correct’ statements from given.

Diagram for Question 7

Options

Option A

Points F, B and C are belonging to different planes.

Option B is correct

A line is formed where two planes intersect.

Option C is correct

Point A, G and E are non-collinear points lying in the same plane.

Option D

Two planes are parallel to each other.

Question 8

1 Mark

In the adjoining figure of ΔEFG, point H is the mid-point of the seg FG. If m∠EFH = 45° and l(EF) = l(EG) = 10 2 cm., then l(EH) = ? cm.

Options

Option A Diagram for Option A
Option B is correct

10

Option C

20

Option D Diagram for Option D

Question 9

1 Mark

The sides forming right angle of a right-angled triangle are 7 cm and 24 cm. Find the radius of the circumcircle of the triangle.

Options

Option A

25.0 cm

Option B is correct

12.5 cm

Option C

12 cm

Option D

13.5 cm

Question 10

1 Mark

The diameter of a ball is 20 cm. Find the volume of the air in the ball. (π = 3.14)

Options

Option A

41866.7 cubic cm.

Option B

4186.67 sq. cm.

Option C

418.67 cm3.

Option D is correct

4186.67 cubic cm.

Question 11

1 Mark

The inner surface of a cylindrical well of height 14m and radius 250 cm is to be plastered with cement-sand layer. At the rate of Rs. 100 per square meter, what will be the total cost in rupees?

Options

Option A is correct

22,000

Option B

22,00,000

Option C

2,20,000

Option D

220

Question 12

1 Mark

In the adjoining figure ∠y = 90°, l(xy) = 8m. l(yz) = 15m, WM ⊥ XZ, WM = 6m. Find the area of the figure.

Diagram for Question 12

Options

Option A

171

Option B is correct

111

Option C

162

Option D

222

Question 13

1 Mark

Two lines are intersecting each other. The measures of the vertically opposite angles in a pair are (2x + 65)° and (7x – 10)°. Find the measures of each remaining angle.

Options

Option A

95°

Option B is correct

85°

Option C

75°

Option D

105°

Question 14

1 Mark

AC is the diameter of a circle. ‘B’ is any point on the circle. Find the false statement from the following. (Choose two correct options)

Options

Option A

∠ BCA < 90°

Option B is correct

Δ BCA is an acute angled triangle

Option C is correct

∠ CAB > 90°

Option D

Measurement of the arc ABC = 180°

Question 15

1 Mark

Two rectangular grounds have area 1541 sq. m. and 759 sq. m. respectively. If both the grounds have same breadth, find the breadth of the ground.

Options

Option A

33 m.

Option B

69 m.

Option C is correct

23 m.

Option D

67 m.

Question 16

1 Mark

Where is the ortho center of a right-angled triangle located?

Options

Option A

In the interior of the triangle.

Option B is correct

On the vertex of the right angle.

Option C

In the exterior of the triangle.

Option D

Anywhere on the triangle.

Question 17

1 Mark

In the adjoining figure ∠TPQ ≅ ∠TPR. Side PQ ≅ side PR. Then by which test Δ QPT and Δ RPT are congruent?

Diagram for Question 17

Options

Option A is correct

S-A-S

Option B

S-S-S

Option C

A-S-A

Option D

S-A-A

Question 18

1 Mark

The measure of an angle is 1/5 times the measure of its supplementary angle. Find the measure of its complementary angle.

Options

Option A

30°

Option B

90°

Option C

150°

Option D is correct

60°

Question 19

1 Mark

Observe the following figure and select the correct statements. (A) Line AB and line BA are different lines. (B) Line AB and line DC intersect at ‘O’. (C) Point C, O and B are noncollinear points.

Diagram for Question 19

Options

Option A

‘A’ and ‘B’ are correct.

Option B is correct

‘B’ and ‘C’ are correct.

Option C

‘A’, ‘B’ and ‘C’ are correct.

Option D

‘A’ and ‘C’ are correct.

Question 20

1 Mark

Find the capacity of a hollow cube whose side is 10 cm. (Choose two correct options)

Options

Option A is correct

1 liter

Option B is correct

1000 cubic cm

Option C

1000 liter

Option D

100 ml

Question 21

1 Mark

Area of a circle is denoted by ‘A’ and radius by ‘r’. Choose the correct statement from the following that states the correct relation of variation between A and r.

Options

Option A Diagram for Option A
Option B Diagram for Option B
Option C Diagram for Option C
Option D is correctDiagram for Option D

Question 22

1 Mark

If the ratio of the measures of angles of ☐ABCD taken in order is 7:8:4:5. Find the type of ☐ABCD.

Options

Option A

Kite

Option B

Rhombus

Option C is correct

Trapezium

Option D

Parallelogram

Question 23

1 Mark

Which of the following can be the measure of an angle in the minor segment?

Options

Option A

45°

Option B is correct

135°

Option C

180°

Option D

90°

Question 24

1 Mark

There is a regular hexagon having each side 14 cm. On every side a semicircle is drawn from outside the hexagon, taking each side as the diameter. Find the perimeter of the figure so formed.

Options

Option A is correct

132 cm

Option B

308 cm

Option C

216 cm

Option D

123 cm

Question 25

1 Mark

In the adjoining figure, an isosceles trapezium is drawn. The measurements of sides of the figure are as follows. l(QR) = l(PS) = 5 units, l(PQ) = 5 units, l(PT) = 4 units. Find the area of ☐PQRS.

Diagram for Question 25

Options

Option A

32 units

Option B

44 sq. units

Option C is correct

32 sq. units

Option D

24 sq. units

Question 26

1 Mark

The ratio of supplementary angle and complementary angle of a given angle is 8:3. Then what will be the ratio of given angle with its supplementary angle?

Options

Option A

4:1

Option B

1:3

Option C is correct

1:4

Option D

1:2

Question 27

1 Mark

What is the cost of fencing a circular garden of radius 28 m with five rounds of wire, if the wire costs Rs. 50 per m?

Options

Option A

Rs. 45,000

Option B

Rs. 46,000

Option C is correct

Rs. 44,000

Option D

Rs. 50,000

Question 28

1 Mark

Which of the following statement is not true? (Choose two correct options) (A) The opposite angles of a parallelogram are congruent. (B) The adjacent sides of a parallelogram are congruent. (C) The diagonals of a parallelogram are congruent. (D) The diagonals of a parallelogram bisect each other.

Options

Option A

statement A

Option B is correct

statement B

Option C is correct

statement C

Option D

statement D

Question 29

1 Mark

The length of a cuboidal tank is one and half time its breadth and height is twice the length. If volume of the tank is 4500 cubic meter, then what is the height of tank? (Choose two correct options)

Options

Option A

10 m.

Option B is correct

3000 cm

Option C is correct

30 m.

Option D

1000 cm

Question 30

1 Mark

If the diameter of a wheel of a tractor is 1.4 m. then how much distance is covered by the wheel in 400 complete rotations.

Options

Option A

1.66 km

Option B

1.56 km

Option C is correct

1.76 km

Option D

1.86 km

Question 31

1 Mark

In the following fig. line l || line m || line n and line x and line y are their transversals. If AB = 18 cm, BC = 30 cm, QR = 21 cm then PR = ?

Diagram for Question 31

Options

Option A

8.4 cm

Option B

14.7 cm

Option C

12.6 cm

Option D is correct

33.6 cm

Question 32

1 Mark

Two angles of measure 40º and 140º with different vertex are drawn then which of the following statement is true?

Options

Option A is correct

The given angles are supplementary angles.

Option B

The given angles are linear pair of angles.

Option C

The given angles are vertically opposite angles.

Option D

The given angles are adjacent angles.

Question 33

1 Mark

The co-ordinate of point P on a number line is – 3/7. The distance between point P and point Q is 2 units then what will be the co-ordinate of point Q? (Choose two correct options)

Options

Option A is correctDiagram for Option A
Option B is correctDiagram for Option B
Option C Diagram for Option C
Option D Diagram for Option D

Question 34

1 Mark

The radius of a circle with center 'O' is 10 cm. The length of a chord is 16 cm. Find the distance of the chord from the center of the circle.

Options

Option A is correct

6 cm

Option B

5 cm

Option C

8 cm

Option D

26 cm

Question 35

1 Mark

A hall has length 30 meter and breadth 9.5 m. For flooring this hall, the square tiles are to be used of half meter side then how many tiles should be required?

Options

Option A

1240

Option B is correct

1140

Option C

1340

Option D

1150

Question 36

1 Mark

The sides forming right angle of a right-angled triangle are 8 cm and 15 cm then what is radius of circumcircle of that triangle?

Options

Option A is correct

8.5 cm

Option B

9.5 cm

Option C

13 cm

Option D

17 cm

Question 37

1 Mark

If the side of an equilateral triangle is 18 cm, then what is its area?

Options

Option A Diagram for Option A
Option B Diagram for Option B
Option C Diagram for Option C
Option D is correctDiagram for Option D

Question 38

1 Mark

A rope of length 216 m. is cut at five places at same distance then what is the length of each piece in cm?

Options

Option A

360 cm

Option B is correct

3600 cm

Option C

36 cm

Option D

36000 cm

Question 39

1 Mark

The curved surface area of a cone is 47.10 sq.cm. If radius of the base is 3 cm then what is its perpendicular height? (p =3.14 cm)

Options

Option A

3 cm

Option B is correct

4 cm

Option C

5 cm

Option D

15.7 cm

Question 40

1 Mark

How many coins of thickness 0.2 cm and diameter 4 cm will be formed by melting a solid metallic cuboid of length 22 cm, breadth 18 cm and height 6 cm?

Options

Option A

935

Option B

954

Option C

594

Option D is correct

945

Question 41

1 Mark

The area of a square is 4.41 sq.cm., then what is its perimeter?

Options

Option A

4.2 cm

Option B

10.4 cm

Option C

8.8 cm

Option D is correct

8.4 cm

Question 42

1 Mark

The base radius of a cylindrical tank is 28 cm. It contains water. A metal cuboid of length 44 cm, breadth 14 cm and height 8 cm is dropped into it. Then what is the increase in the level of water in tank?

Options

Option A is correct

2 cm

Option B

2.5 cm

Option C

3 cm

Option D

1.5 cm

Question 43

1 Mark

The length of side of a rhombus is 17 cm. If the length of one diagonal is 16 cm then what is the length of other diagonal?

Options

Option A is correct

30 cm

Option B

17 cm

Option C

8 cm

Option D

34 cm

Question 44

1 Mark

The measures of exterior angles of a triangle are 115º and 117º respectively, then which type of triangle is it?

Options

Option A is correct

Acute angled triangle

Option B

Obtuse angled triangle

Option C

Right angled triangle

Option D

Equilateral triangle

Question 45

1 Mark

The length of a diagonal of a square is 11 cm then what is the length of its side?

Options

Option A Diagram for Option A
Option B Diagram for Option B
Option C is correctDiagram for Option C
Option D Diagram for Option D

Question 46

1 Mark

The measure of a minor arc is 160° then what is the measure of corresponding major arc?

Options

Option A

160°

Option B

320°

Option C is correct

200°

Option D

80°

Question 47

1 Mark

In a circle, the measure of a major arc is 60° more than double the measure of its minor arc. What will be the measure of its major arc?

Options

Option A

100°

Option B

300°

Option C

220°

Option D is correct

260°

Question 48

1 Mark

Which of the following options indicate the volume of a sphere?

Options

Option A Diagram for Option A
Option B is correctDiagram for Option B
Option C Diagram for Option C
Option D Diagram for Option D

Question 49

1 Mark

If a supplementary angle of an angle’s complementary angle is 108°, find the measure of the angle.

Options

Option A

72°

Option B is correct

18°

Option C

98°

Option D

198°

Question 50

1 Mark

In the adjoining figure, the diagonal of a square is 12 cm. Find the length of every side.

Diagram for Question 50

Options

Option A Diagram for Option A
Option B Diagram for Option B
Option C Diagram for Option C
Option D is correctDiagram for Option D

Question 51

1 Mark

Four vertices of a square lie on the circle as shown in the figure. The center of the circle is ‘O’ and radius is 7cm. Find the area of the shaded portion.

Diagram for Question 51

Options

Option A

54 sq. cm

Option B

55 sq. cm

Option C is correct

56 sq. cm

Option D

57 sq. cm

Question 52

1 Mark

In the adjoining figure, l, m, n are parallel lines. m ∠ DAO = 60° m ∠ OCE = 35°, then m ∠ AOC = ?

Diagram for Question 52

Options

Option A

25°

Option B is correct

95°

Option C

85°

Option D

105°

Question 53

1 Mark

Which of the options given below are incorrect statements? (Select two correct alternatives) (A) A ray has a midpoint. (B) A line has a midpoint. (C) Chord of a circle has a midpoint. (D) Perpendicular bisector of a line segment passes through its midpoint.

Options

Option A is correct

A

Option B is correct

B

Option C

C

Option D

D

Question 54

1 Mark

By which of tests, Δ ABC and Δ DCB from the given figure will be congruent?

Diagram for Question 54

Options

Option A

SSS test

Option B

SAA test

Option C

ASA test

Option D is correct

SAS test

Question 55

1 Mark

□ ABCD is a cyclic quadrilateral. Point E lies on the ray BC as B – C – E. If m ∠ DCE = 95°, then m ∠ DAB = ?

Diagram for Question 55

Options

Option A

85°

Option B is correct

95°

Option C

190°

Option D

170°

Question 56

1 Mark

From a rectangular thermocol sheet with dimension 20 cm × 10 cm, a rectangular piece of 2 cm × 5 cm dimension is cut. Which of the following sentences will be correct for the thermocol sheet?

Diagram for Question 56

Options

Option A

Perimeter will increase

Option B

Perimeter will decrease

Option C is correct

Perimeter will remain same

Option D

Perimeter will get doubled

Question 57

1 Mark

In the figure, line l and m intersect in point O. Find the value of ‘y’.

Diagram for Question 57

Options

Option A

164°

Option B

56°

Option C

34°

Option D is correct

146°

Question 58

1 Mark

Which of the following conditions should be given to make the total surface area of a sphere and cylinder to be equal?

Options

Option A

Diameter of a sphere should be equal to the radius of a cylinder.

Option B is correct

Radius and height of a cylinder is equal to the radius of a sphere.

Option C

Radius of a cylinder should be double the radius of sphere.

Option D

Height of a cylinder should be equal to the diameter of the sphere.

Question 59

1 Mark

Which of the following options is not a pythagorean triplet?

Options

Option A

(3, 4, 5)

Option B

(7, 24, 25)

Option C

(8, 15, 17)

Option D is correct

(5, 13, 14)

Question 60

1 Mark

What is the product of two integers between which -(119/13) lie?

Options

Option A

65

Option B is correct

90

Option C

-72

Option D

72

Question 61

1 Mark

The length, breadth and height of a cuboid is ‘l’ cm ‘b’ cm, ‘h’ cm. If l b = 60 sq. cm, bh = 24 sq. cm, hl = 40 sq. cm, then find the volume of cuboid.

Options

Option A

248 cu.cm

Option B is correct

240 cu.cm

Option C

600 cu.cm

Option D

420 cu.cm

Question 62

1 Mark

A semicircle is drawn over a diameter. The circumference of the semicircle is 72 units. l(BC) = l(AO) = l(OC). Find the perimeter of Δ ABC.

Diagram for Question 62

Options

Option A is correctDiagram for Option A
Option B Diagram for Option B
Option C Diagram for Option C
Option D Diagram for Option D

Question 63

1 Mark

Which of the following options is the co-efficient form of the polynomial

Diagram for Question 63

Options

Option A

(1, – 4)

Option B is correct

(1, 0, 0, 0, – 4, 0)

Option C

(1, 0, 0, 0, – 4)

Option D

(1, 0, 0, 0, 4)

Question 64

1 Mark

In Δ PQR, angle bisectors of ∠ Q and ∠ R intersect at point O. m ∠ O = 130°, m ∠ P = ?

Diagram for Question 64

Options

Option A

50°

Option B

100°

Option C is correct

80°

Option D

130°

Question 65

1 Mark

If a transversal intersects two parallel lines, then find the ratio of the number of pairs of alternate angles to the number of pairs of corresponding angles so formed.

Options

Option A is correct

1:2

Option B

2:3

Option C

3:2

Option D

2:5

Question 66

1 Mark

Find the ratio of the total surface area of the hemisphere with diameter 28 cm to surface area of a sphere having radius 14 cm.

Options

Option A

2:1

Option B

4:3

Option C is correct

3:4

Option D is correct

1:2

Question 67

1 Mark

The measure of a given angle is 1/4 times that of its supplementary angle. Find the measure of its complementary angle.

Options

Option A

36°

Option B

45°

Option C is correct

54°

Option D

60°

Question 68

1 Mark

Find the measure of the angle between the hour hand and minute hand of a clock at 15 minutes past 2.

Options

Option A Diagram for Option A
Option B is correctDiagram for Option B
Option C Diagram for Option C
Option D Diagram for Option D

Question 69

1 Mark

The diagonal of a square is 25√2 cm. Find the area of the square.

Options

Option A is correct

625 cm²

Option B

525 cm²

Option C

825 cm²

Option D

725 cm²

Question 70

1 Mark

How much less is the area of a square whose perimeter is 44 cm. than the area of a circle whose circumference is 44 cm.

Options

Option A is correct

33 cm²

Option B

32 cm²

Option C

30 cm²

Option D

23 cm²

Question 71

1 Mark

A bus has wheels of diameter 1.4m. Travelling from one town to other, the wheels complete 20,000 rotations. Find the distance covered by the bus. [Select two correct alternatives]

Options

Option A is correct

88 km

Option B

44 km

Option C is correct

88000 m

Option D

44000 m

Question 72

1 Mark

How much water will a cylindrical tank contain if its height is 10 m and diameter is 14m.

Options

Option A

154000 liters

Option B is correct

1540000 liters

Option C

2540000 liters

Option D

3540000 liters

Question 73

1 Mark

The diagonals of a rhombus are 24 cm and 32 cm. Find the perimeter of the rhombus.

Options

Option A

40 cm

Option B is correct

80 cm

Option C

100 cm

Option D

120 cm

Question 74

1 Mark

A cuboid box has length 60 cm breadth 18 cm and height 15 cm. How many cubical boxes having each side 6 cm. will be contained in the box.

Options

Option A

55

Option B

61

Option C

65

Option D is correct

75

Question 75

1 Mark

Observe the given figure and find the odd term.

Diagram for Question 75

Options

Option A Diagram for Option A
Option B Diagram for Option B
Option C is correctDiagram for Option C
Option D Diagram for Option D

Question 76

1 Mark

The perimeter of a semi-circular garden is 180 m. Find the area of the garden.

Options

Option A

3850 sq.m.

Option B

3350 sq.m.

Option C

2250 sq.m

Option D is correct

1925 sq.m.

Question 77

1 Mark

A pit 60 m long, 40 m wide and 5 m deep was dug and the soil was spread evenly over a road of length 1 km. and breadth 24 m. What was the thickness of the soil spread?

Options

Option A is correct

50 cm

Option B

5 cm

Option C is correct

0.5 m

Option D

1.5 m

Question 78

1 Mark

The sides forming the right angle of a right-angled triangle are 5 cm. and 12 cm. Find the radius of the circumcircle of the triangle

Options

Option A is correct

6.5 cm

Option B

7.5 cm

Option C

8.5 cm

Option D

5.5 cm

Question 79

1 Mark

Total surface area of a cube is 384cm². Find the volume of that cube.

Options

Option A is correct

512 cu. cm

Option B

343 cu. cm

Option C

0.512 cu. m

Option D

0.343 cu. m

Question 80

1 Mark

Solve.

Diagram for Question 80

Options

Option A is correctDiagram for Option A
Option B Diagram for Option B
Option C Diagram for Option C
Option D is correctDiagram for Option D

Question 81

1 Mark

Find the perpendicular height of an equilateral triangle whose side is 12 cm.

Options

Option A Diagram for Option A
Option B Diagram for Option B
Option C is correctDiagram for Option C
Option D is correctDiagram for Option D

Question 82

1 Mark

In the above trapezium PQRS side PQ 11 side SR. The measurements of the sides are given in the figure. observe the figure and find the area of the trapezium.

Diagram for Question 82

Options

Option A is correct

624 m²

Option B

524 m²

Option C

6.24 m²

Option D

5.24 m²

Question 83

1 Mark

The area of an equilateral triangle is 100sqrt3100 \\sqrt{3} sq.cm. Find the perimeter of that equilateral triangle.

Options

Option A is correct

60 cm

Option B

50 cm

Option C

48 cm

Option D

81 cm

Question 84

1 Mark

The difference between half circumference of a circle and its diameter is 4 cm. Find the area of the circle.

Options

Option A

154 sq.cm.

Option B

77 sq.cm.

Option C

19.25 sq.cm.

Option D is correct

38.50 sq.cm.

Explanation

Let the radius of the circle be rr. The half circumference is πr\pi r and the diameter is 2r2r. Given that πr2r=4\pi r - 2r = 4. Factoring out rr, we get r(π2)=4r(\pi - 2) = 4. Substituting π=227\pi = \frac{22}{7}, we have r(2272)=4    r(22147)=4    r(87)=4r(\frac{22}{7} - 2) = 4 \implies r(\frac{22 - 14}{7}) = 4 \implies r(\frac{8}{7}) = 4. Solving for rr, r=4×78=72r = 4 \times \frac{7}{8} = \frac{7}{2} cm. The area of the circle is A=πr2=227×(72)2=227×494=22×74=11×72=772=38.5A = \pi r^2 = \frac{22}{7} \times (\frac{7}{2})^2 = \frac{22}{7} \times \frac{49}{4} = \frac{22 \times 7}{4} = \frac{11 \times 7}{2} = \frac{77}{2} = 38.5 sq.cm.

Question 85

1 Mark

In the adjoining figure line ll|| line mm and line pp is the transversal. Observe the figure and find the value of w\angle w.

Diagram for Question 85

Options

Option A is correct

4545^{\circ}

Option B

135135^{\circ}

Option C

130130^{\circ}

Option D

9090^{\circ}

Explanation

Let's interpret the given angle positions. Let the transversal intersect line ll at point AA and line mm at point BB. Angle 3x3x is exterior above line ll. Let's assume it's the top-left exterior angle. Angle xx is interior below line ll. For a valid solution, we assume it's the bottom-right interior angle at line ll. The interior angle adjacent to the exterior angle 3x3x (top-left) is 1803x180^{\circ} - 3x. This is the top-left interior angle. Since lines ll and mm are parallel, the alternate interior angles are equal. The top-left interior angle and the bottom-right interior angle are alternate interior angles. Therefore, 1803x=x180^{\circ} - 3x = x. 180=4x180^{\circ} = 4x x=1804x = \frac{180^{\circ}}{4} x=45x = 45^{\circ}. Now, angle ww is interior below line mm. Let's assume it's the bottom-right interior angle at line mm. Since lml || m, the corresponding angles are equal. The bottom-right interior angle at line ll is xx, and the bottom-right interior angle at line mm is ww. Therefore, w=xw = x. Substituting the value of xx, we get w=45w = 45^{\circ}.

Question 86

1 Mark

How many more segments are formed by joining six collinear points to each other than by joining five non-collinear points to each other?

Options

Option A

9

Option B

7

Option C

8

Option D is correct

5

Explanation

The number of segments formed by joining nn distinct points is given by the combination formula (n2)=n(n1)2\binom{n}{2} = \frac{n(n-1)}{2}.

Part 1: Segments formed by joining six collinear points. For n=6n=6 collinear points, the number of segments is (62)=6×(61)2=6×52=302=15\binom{6}{2} = \frac{6 \times (6-1)}{2} = \frac{6 \times 5}{2} = \frac{30}{2} = 15.

Part 2: Segments formed by joining five non-collinear points. For n=5n=5 non-collinear points, the number of segments is (52)=5×(51)2=5×42=202=10\binom{5}{2} = \frac{5 \times (5-1)}{2} = \frac{5 \times 4}{2} = \frac{20}{2} = 10.

To find how many more segments are formed, we subtract the second number from the first: Difference =1510=5= 15 - 10 = 5. Therefore, 55 more segments are formed.

Question 87

1 Mark

In the adjoining PQR\triangle PQR, ray PA and ray QB are the bisectors of P\angle P and Q\angle Q respectively. If R=70\angle R=70^\circ. Find mPMQm \angle PMQ.

Diagram for Question 87

Options

Option A

120°

Option B

130°

Option C is correct

125°

Option D

135°

Explanation

In PQR\triangle PQR, the sum of angles is 180180^\circ. Given R=70\angle R=70^\circ, we have P+Q=18070=110\angle P + \angle Q = 180^\circ - 70^\circ = 110^\circ. Since PA and QB are angle bisectors, in PMQ\triangle PMQ, QPM=12P\angle QPM = \frac{1}{2}\angle P and PQM=12Q\angle PQM = \frac{1}{2}\angle Q. The sum of angles in PMQ\triangle PMQ is 180180^\circ, so PMQ+QPM+PQM=180\angle PMQ + \angle QPM + \angle PQM = 180^\circ. This simplifies to PMQ+12(P+Q)=180\angle PMQ + \frac{1}{2}(\angle P + \angle Q) = 180^\circ. Substituting the sum of P\angle P and Q\angle Q, we get PMQ+12(110)=180\angle PMQ + \frac{1}{2}(110^\circ) = 180^\circ. Thus, PMQ+55=180\angle PMQ + 55^\circ = 180^\circ, which means PMQ=18055=125\angle PMQ = 180^\circ - 55^\circ = 125^\circ. Alternatively, the angle formed by two angle bisectors is given by 90+12R=90+12(70)=90+35=12590^\circ + \frac{1}{2}\angle R = 90^\circ + \frac{1}{2}(70^\circ) = 90^\circ + 35^\circ = 125^\circ.

Question 88

1 Mark

In the adjoining PQR\triangle PQR, AQP=130\angle AQP=130^\circ, BRP=140\angle BRP=140^\circ, l(PQ)=16l(PQ)=16 cm, l(PR)=12l(PR)=12 cm. Find l(QR)l(QR).

Diagram for Question 88

Options

Option A

17 cm

Option B

25 cm

Option C

18 cm

Option D is correct

20 cm

Explanation

Given AQP=130\angle AQP=130^\circ, PQR=180130=50\angle PQR = 180^\circ - 130^\circ = 50^\circ (linear pair). Given BRP=140\angle BRP=140^\circ, PRQ=180140=40\angle PRQ = 180^\circ - 140^\circ = 40^\circ (linear pair). In PQR\triangle PQR, the sum of angles is 180180^\circ, so QPR+PQR+PRQ=180\angle QPR + \angle PQR + \angle PRQ = 180^\circ. Substituting the values, QPR+50+40=180\angle QPR + 50^\circ + 40^\circ = 180^\circ, which gives QPR+90=180\angle QPR + 90^\circ = 180^\circ. Therefore, QPR=90\angle QPR = 90^\circ. Since PQR\triangle PQR is a right-angled triangle at P, we can use the Pythagorean theorem: PQ2+PR2=QR2PQ^2 + PR^2 = QR^2. Substituting the given lengths, 162+122=QR216^2 + 12^2 = QR^2. This simplifies to 256+144=QR2256 + 144 = QR^2, so 400=QR2400 = QR^2. Taking the square root, QR=400=20QR = \sqrt{400} = 20 cm.

Question 89

1 Mark

Opposite angles of a cyclic quadrilateral are (3x+10)(3x+10)^\circ and (4x+30)(4x+30)^\circ. Find the measures of these angles.

Options

Option A is correct

70°, 110°

Option B

115°, 65°

Option C

120°, 60°

Option D

112°, 68°

Explanation

In a cyclic quadrilateral, the sum of opposite angles is 180180^\circ. Given the opposite angles are (3x+10)(3x+10)^\circ and (4x+30)(4x+30)^\circ, we set their sum equal to 180180^\circ: (3x+10)+(4x+30)=180(3x+10) + (4x+30) = 180. Combining like terms, 7x+40=1807x + 40 = 180. Subtracting 4040 from both sides, 7x=1407x = 140. Dividing by 77, x=20x = 20. Now, substitute x=20x=20 back into the expressions for the angles: First angle =(3(20)+10)=(60+10)=70= (3(20)+10)^\circ = (60+10)^\circ = 70^\circ. Second angle =(4(20)+30)=(80+30)=110= (4(20)+30)^\circ = (80+30)^\circ = 110^\circ. The measures of the angles are 7070^\circ and 110110^\circ.

Question 90

1 Mark

In the adjoining PQR\triangle PQR, PQR=90\angle PQR=90^\circ and QMPRQM \perp PR, PQ=12PQ=12 cm, QR=16QR=16 cm. Find l(QM)l(QM).

Diagram for Question 90

Options

Option A

2.4 cm

Option B

19.2 cm

Option C

4.8 cm

Option D is correct

9.6 cm

Explanation

In the right-angled PQR\triangle PQR with PQR=90\angle PQR=90^\circ, we are given PQ=12PQ=12 cm and QR=16QR=16 cm. First, find the length of the hypotenuse PR using the Pythagorean theorem: PQ2+QR2=PR2PQ^2 + QR^2 = PR^2. So, 122+162=PR212^2 + 16^2 = PR^2, which means 144+256=PR2144 + 256 = PR^2. Thus, PR2=400PR^2 = 400, and PR=400=20PR = \sqrt{400} = 20 cm. The area of PQR\triangle PQR can be calculated as 12×PQ×QR=12×12×16=96\frac{1}{2} \times PQ \times QR = \frac{1}{2} \times 12 \times 16 = 96 cm2^2. The area can also be expressed as 12×PR×QM\frac{1}{2} \times PR \times QM, where QM is the altitude to the hypotenuse. So, 96=12×20×QM96 = \frac{1}{2} \times 20 \times QM. This simplifies to 96=10×QM96 = 10 \times QM. Therefore, QM=9610=9.6QM = \frac{96}{10} = 9.6 cm.

Question 91

1 Mark

In the adjoining figure PQRS is a square having side 28 cm. Points A, B, C and D are the midpoints of side PQ, side QR, side RS, side SP respectively. Find the area of square ABCD.

Diagram for Question 91

Options

Option A

784 sq.cm.

Option B is correct

392 sq.cm.

Option C

196 sq.cm.

Option D

616 sq.cm.

Explanation

Given that PQRS is a square with a side length of 28 cm. The points A, B, C, and D are the midpoints of the sides PQ, QR, RS, and SP respectively.

  1. Calculate the area of the outer square PQRS: Area of square PQRS = side × side = 28 cm × 28 cm = 784 cm².

  2. Determine the dimensions of the corner triangles: Since A, B, C, D are midpoints, they divide each side of the square PQRS into two equal halves. Therefore:

    • PA = AQ = QB = BR = RC = CS = SD = DP = 28 cm / 2 = 14 cm.
  3. Calculate the area of one corner triangle: Consider the right-angled triangle formed at each corner, for example, triangle QAB. The legs of this triangle are AQ and QB.

    • Base (AQ) = 14 cm
    • Height (QB) = 14 cm Area of ΔQAB = (1/2) × base × height = (1/2) × 14 cm × 14 cm = (1/2) × 196 cm² = 98 cm².
  4. Calculate the total area of the four corner triangles: There are four such congruent triangles (ΔQAB, ΔRBC, ΔSCD, ΔPDA). Total area of 4 triangles = 4 × 98 cm² = 392 cm².

  5. Calculate the area of the inner square ABCD: The area of the inner square ABCD can be found by subtracting the total area of the four corner triangles from the area of the outer square PQRS. Area of square ABCD = Area of square PQRS - Total area of 4 triangles Area of square ABCD = 784 cm² - 392 cm² = 392 cm².

Alternatively, we could find the side length of square ABCD using the Pythagorean theorem for one of the triangles, e.g., ΔQAB: AB² = AQ² + QB² = 14² + 14² = 196 + 196 = 392. Since ABCD is a square, its area is AB². Area of square ABCD = 392 cm².