Question

If 105 ^cm2 square is the area of circle then its circumference is

Answer 1

Answer:

$are a \: of \: circle \: = \pi \: r {}^{2} \\ 105 = \frac{22}{7} \times r {}^{2} \\ r {}^{2} = \frac{735}{22} \\ circumference = \: 2\pi \: r \\ = 2 \times \frac{22}{7} \times \sqrt{ \frac{735}{22} }$