Question

The ratio of the circumference of a circle to its ____ is $\pi$.

• A. radius
• B. area
• C. $radiu{s}^2$
• D. diameter

Answer 1

The correct option is D

diameter

Circumference of a circle is $2\pi r$.

Diameter of a circle, d = 2r,
where r is the radius of the circle.

$\frac{Circumference}{Diameter}=\frac{2\pi r}{2r}=\pi$

Therefore, ratio of the circumference of a circle to its diameter is equal to $\pi$.