Question

What is the diameter of a circle whose area is $16\pi$?

Answer 1

Step-1: Use the formula for area of circle to compute the radius:

The area of circle is $\pi r^2$,

Find the value of radius as shown:

$\begin{array}{rcl}\pi r^2& =& 16\pi \\ & \Rightarrow & r^2=16\\ & \Rightarrow & r=4\end{array}$

Step-2: Find the diameter:

The relation between radius and diameter can be given as:

$$\begin{gathered} d=2r \\ d=2\left(4\right) \\ d=8 \end{gathered}$$

Hence, the diameter of the circle is $\mathbf{8}\mathbf{}\mathbf{units}$.