Question

The area of a circle is 1386 sq.cm; find its circumference.

Answer 1

Area of circle = 1386 cm²
πr² = 1386

`22/7r^2 = 1386`

`r^2 = 1386 xx 7/22`

`r^2 = 441`

r = `sqrt(441)`

r = 21 cm

circumference = `2pir`

= `2 xx 22/7 xx 21`

= 132 m