Question

What is the circumference of the circle with a diameter of $17$ meters?

Answer 1

Hint: In this problem we need to calculate the circumference of the circle with the given diameter. We know that the circumference of the circle is given by $2\pi r$ where $r$ is the radius of the circle. But in the problem, we have the diameter of the circle. So, we will calculate the radius of the circle by using the formula $r=\dfrac{d}{2}$ where $d$ is the diameter of the circle. After calculating the radius of the circle, we will use the formula $C=2\pi r$ and calculate the circumference of the circle.

Complete step by step answer:
Given that the diameter of the circle is $17$ meters.

Let $r$ be the radius of the circle. We know that the relation between diameter and radius of the circle is given by $r=\dfrac{d}{2}$. From this relation the radius of the circle having diameter $17$meters would be
$\begin{align}
  & r=\dfrac{17}{2} \\
 & \Rightarrow r=8.5 \\
\end{align}$
We know that the circumference of the circle having radius $r$ is given by $C=2\pi r$. So, the circumference of the circle having radius $8.5$ is given by
$C=2\pi \left( 8.5 \right)$
We know that the value $\pi =3.14$, substituting this value in the above equation, then we will get
$\begin{align}
  & C=2\times 3.14\times 8.5 \\
 & \Rightarrow C=53.38 \\
\end{align}$
Hence the circumference of the circle is $53.38$ centimeter.

Note: In this problem we have the diameter, so we can directly use the formula $C=\pi d$ to find the circumference of the circle. There is no need to calculate the radius of the circle for the circumference.