Measurements (Term 2) - Circles — Practice

Question 1

Find the circumference of a circle of radius 21 cm (π = 22/7).

Accepted Answer

2 × 22/7 × 21 = 132 cm.

Question 2

Find the area of a circle of diameter 28 cm (π = 22/7).

Accepted Answer

r = 14; A = 22/7 × 14 × 14 = 616 cm².

Question 3

The circumference of a circle is 66 cm. Find its radius (π = 22/7).

Accepted Answer

2 × 22/7 × r = 66 → r = 10.5 cm.

Question 4

A circular garden of radius 35 m has a 7 m wide path around it. Find the area of the path (π = 22/7).

Accepted Answer

R = 42, r = 35; π(R² − r²) = 22/7 × (1764 − 1225) = 22/7 × 539 = 1694 m².

Question 5

Find the area of a circle of radius 10 cm (π = 3.14).

Accepted Answer

3.14 × 100 = 314 cm².

Question 6

What is the value of π as a fraction?

Accepted Answer

22/7 (approximately).

Practice — Measurements (Term 2) - Circles