Question

Circumference of a circle with radius $r$ and diameter $d$ is ____.

• A. $\pi r$
• B. $\pi r^2$
• C. $\pi d$
• D. $\pi d^2$

Answer 1

The correct option is C

$\pi d$

Circumference of a circle is $2\pi r$ or $\pi d$ as $d=2r$.