Question

the circumference of a circle can be found using the formula ( c = 2pi r ). which is an equivalent equation solved for ( r )? ( r = cpi ), ( r = c(2pi) ), ( r=\frac{c}{2pi} ), ( r=\frac{2pi}{c} )

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.
$$\frac{C}{2\pi}=r$$

Answer:

\( r=\frac{C}{2\pi} \) (the third option)