Question

When the circumference and area of a circle are numerically equal, find the numerical value of its diameter.

• A. $\frac{\pi }{2}$
• B. $8$
• C. $2\pi$
• D. $4$

Answer 1

The correct option is D $4$

Circumference of circle $=$ Area of circle

$\Rightarrow 2\pi r=\pi r^2\Rightarrow d={\left(\frac{d}{2}\right)}^2\Rightarrow 4d=d^2\Rightarrow d=4$