AREA AND PERIMETER (CDS)

Total Questions: 116

61. A copper wire when bent in the form of a square encloses an area of 121 cm² . If the same wire is bent in the form of a circle, it encloses an area equal to [2017 (I) Morning Shift]

Correct Answer: (c) 154 cm²
Solution:Let the length of the square be a cm

62. A field is divided into four regions as shown in the given figure. What is the area of the field in square metres? [2017 (I) Morning Shift]

Correct Answer: (c)
Solution:

63. Solve the following equation [2016 (II) Evening Shift]

Correct Answer: (c)
Solution:





64. What is area of largest triangle inscribed in a semi-circle of radius r units? [2016 (II) Evening Shift]

Correct Answer: (a) r² square units
Solution:Largest triangle inscribed in a semi-circle is ∆ABC.

65. The diameter of the front wheel of an engine is 2x cm and that of rear wheel is 2 y cm. To cover the same distance, what is the number of times the rear wheel revolves when the front wheel revolves n times? [2016 (II) Evening Shift]

Correct Answer: (c)
Solution:Diameter of front wheel = 2x cm

66. The wheels of a car are of diameter 80 cm each. The car is travelling at a speed of 66 km/h. What is the number of complete revolutions each wheel makes in 10 min? [2016 (II) Evening Shift]

Correct Answer: (c) 4375
Solution:Given, radius of wheel = 80/2 cm = 40 cm

67. What is the area of a triangle with sides of length 12 cm, 13 cm and 5 cm? [2016 (II) Evening Shift]

Correct Answer: (a) 30 cm²
Solution:Given, the length of the sides are a = 12 cm, b = 13 cm

68. If the perimeter of a circle is equal to that of a square, then what is the ratio of area of circle to that of square? [2016 (II) Evening Shift]

Correct Answer: (b) 14 : 11
Solution:Let r be the radius of a given circle and a be the length of each side of a given square.

69. Two circles touch externally and sum of their areas is 130 2 π cm and the distance between their centres is 14 cm. What is the difference in the radii of the circles? [2016 (II) Evening Shift]

Correct Answer: (b) 6 cm
Solution:Let r₁ and r₂ be the radius of the two circles.

70. What is the number of rounds that a wheel of diameter 5/11 m will make in traversing 7 km ? [2016 (II) Evening Shift]

Correct Answer: (d) 4900
Solution:Given, diameter of wheel = 5/11 m