Question

If the area of a circle is 1386 cm², its radius is ______.

Options

• 14 cm

• 10.5 cm

• 21 cm

• 28 cm

Answer 1

If the area of a circle is 1386 cm², its radius is 21 cm.

Explanation:

The area of the circle is given by the formula:

Area = πr²

Given the area is 1386 cm² and using `π = 22/7`,

`1386 = 22/7 r^2`

`r^2 = (1386 xx 7)/22`

r² = 63 × 7

r² = 441

r = `sqrt(441)`

r = 21 cm

So, the radius of the circle is 21 cm.