Question

circumference of a circle is 178 cm . find its radius . ​

Answer 1

$c = 178 \\ 2\pi \:r = 178 \\ 2 \times \frac{22}{7} \times r = 178 \\ r = \frac{178 \times 7}{22 \times 2} \\ r = 28.31$

Answer 2

Hope it helps.........