A semicircular cut is made in a rectangle with sides of 20 m and 22 m. Find the radius

A semicircular cut is made in a rectangle with sides of 20 m and 22 m. Find the radius of a semicircle if the area of the resulting figure is 361.5 m2.

First, find the area of ​​the original rectangle (before cutting the semicircle). The area of ​​a rectangle is equal to the product of the length of its sides. We get that the area of ​​the rectangle is:
20 * 22 = 440 m.
Now, if we subtract the area of ​​the resulting shape after cutting out the semicircle from the area of ​​the original rectangle, we get the area of ​​the semicircle:
440 – 361.5 = 78.5 sq. M. is the area of ​​a semicircle.
Now we find the radius of the semicircle. We know that the area of ​​a semicircle is пr ^ 2/2.
That is, пr ^ 2/2 = 78.5. We express r:
r =√ (78.5 * 2 / P)
r = √ (78.5 * 2 / 3.14)
r = √ 50
r = 7.07