Question

A circular disc has circumference 250 cm. Calculate the radius of the disc.

Answer 1

$\textit{circumference of a circle}\\\\ C=2\pi r ~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ C=250 \end{cases}\implies 250=2\pi r\implies \cfrac{250}{2\pi }=r\implies \stackrel{cm}{39.79}\approx r$