The area of a circle is 38.5cm2. Find its diameter [take \(\pi = \frac{22}{7}\)]

Explanation

\(\pi r^2 = 38.5\\
\frac{}{} = r^2 = 38.5\\
r^2 = \frac{38.5 \times 7}{22}\\
r = \sqrt{12.25} = 3.5\\
diameter = 2r = 2 \times 3.5 = 7cm\)