Use the composite area method to locate the centroid of the shaded area shown, which was created by cutting a semicircle of diameter $r$ from a quarter circle of radius $r$.
$\bar{x} = \dfrac{2r}{\pi} = 0.6366r$
![diagram](./images/722-quarter-and-semi-circles.png)
Use the composite area method to locate the centroid of the shaded area shown, which was created by cutting a semicircle of diameter $r$ from a quarter circle of radius $r$.
$\bar{x} = \dfrac{2r}{\pi} = 0.6366r$