OpenSAT

The area of a sector of a circle is given by the formula $\frac{\theta}{360} \pi r^2$, where $\theta$ is the central angle in degrees and $r$ is the radius. In this case, we have $\theta = 72$ and $r = 5$, so the area of the sector is $\frac{72}{360} \pi (5^2) = \frac{1}{5} \pi (25) = 5\pi$ square units.