Q.1 Find the area of rhombus whose diagonals are 5cm & 8cm ?
A) 20
B) 21
C) 22
D) 23
Ans. A
Area of rhombus = ½ * product of diagonals
½ * 5 * 8 = 20
Q.2 Circumference of circle is 88m. Find its area ?
A) 616 m2
B) 618 m2
C) 620m2
D) 622m2
Ans. A
Area = (Circumference)2/ 4 p
(88)2/4p = 88*88*7/4*22 = 616m2
Q.3 Find the area of triangle whose sides measure 4,6 & 8cm ?
A) 3v15
B) 2v15
C) 4v15
D) 6v15
Ans. A
A=4 , b=6 , c=8
Therefore,
S=a+b+c/2 = 9
Now, area = vS(s-a) (s-b) (s-c)
Or v9(9-4) (9-6) (9-8)
Or v9*5*3*1
Or 3v15
Q.4Three metal cubes having volumes 125 cubic cm, 64 cubic cm and 27 cubic cm are melted to form a new cube. Find the edge of the new cube.
A) 10 cm
B) 8 cm
C) 7 cm
D) 6 cm
Ans. D
Total volume = 216 cm3
Edge = 6 cm
Q.5 The radius of the base of a right circular cone is 6 cm and its slant height is 28 cm. Find the curved surface area of the cone.
A) 1268 sq.cm
B) 865 sq.cm
C) 662 sq.cm
D) 528 sq.cm
Ans. D
Curved surface area of a cone = prl
= p × 6 × 28
= 528 cm2
