Question

in the formula for circumference of a circle ( c = 2pi r ), solve for ( r ).

Explanation:

Step1: Isolate \( r \)

Given \( C = 2\pi r \), divide both sides by \( 2\pi \).
$$\frac{C}{2\pi}=\frac{2\pi r}{2\pi}$$

Step2: Simplify

Simplify the right - hand side. Since \(\frac{2\pi r}{2\pi}=r\), we get \( r=\frac{C}{2\pi} \).

Answer:

\( r=\frac{C}{2\pi} \)