Perimeter and Area — Practice

Question 1

Find the area of a triangle with base 16 cm and height 9 cm.

Accepted Answer

Area = (1/2) x 16 x 9 = 72 sq cm.

Question 2

A parallelogram has area 180 sq cm and base 12 cm. Find its height.

Accepted Answer

Height = Area / base = 180 / 12 = 15 cm.

Question 3

Find the radius of a circle with circumference 88 cm. (Use pi = 22/7)

Accepted Answer

2 x (22/7) x r = 88 -> r = (88 x 7)/(2 x 22) = 616/44 = 14 cm.

Question 4

A rectangular park 30 m by 24 m has a 3 m wide path around it inside the park. Find the area of the path.

Accepted Answer

Inner length = 30 - 6 = 24 m, inner breadth = 24 - 6 = 18 m, inner area = 432 sq m. Outer area = 720 sq m. Path area = 720 - 432 = 288 sq m.

Question 5

How many times will a wheel of radius 35 cm rotate to cover 22 m?

Accepted Answer

Circumference = 2 x (22/7) x 35 = 220 cm = 2.2 m. Number of rotations = 22 / 2.2 = 10.

Practice — Perimeter and Area