Show that the radius of a shooting circle is 9m if its area is 107.17m² and pi is 3.14.

2.1.1
The area of a semi-circle is given by the formula $A = \frac{1}{2} \pi r^2$.
We are given that the area of one shooting circle is $107.17 \text{ m}^2$ and $\pi = 3.14$. We need to show that the radius $r$ is $9 \text{ m}$.