Question

The sum of circumference and diameter of a circle is $145\text{cm}$, find the diameter of the circle.

Answer 1

Let $r$ be the radius of the circle. So, diameter $d$ will be equal to $2r$.

$\begin{array}{cc}2\pi r+2r& =145\left[\text{Given}\right]\\ 2r\left(\frac{22}{7}+1\right)& =145\\ d\times \frac{29}{7}& =145\\ d& =35\text{cm}\end{array}$

Hence, the diameter of the circle is $35\text{cm}$.