Question

the formula for the circumference of a circle is ( c = 2pi r ). use this formula to write a formula for the radius of a circle.
a ( r = 2pi c )
b ( r = c - 2pi )
c ( r=\frac{c}{2pi} )
d ( r=\frac{2pi}{c} )

Explanation:

Step1: Isolate the variable \( r \)

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

Step2: Simplify the equation

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

Answer:

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