Question

6/17
what is the formula for the circumference of a circle with radius $r$?
$2\pi r$
$\pi r^{2}$
$r^{2}$
$2r$

Explanation:

Step1: Recall circumference definition

Circumference = $2 \times \pi \times \text{radius}$

Step2: Match to options

The formula $2\pi r$ matches option A.

Answer:

A. $2\pi r$