Answer:
Subtract the area of the semicircle from the area of the rectangle
Explanation:
Hi there!
1) Find the area of the rectangle

Plug in the given side lengths 10 and 8 and solve for the area of the rectangle. Disregard the semicircle.
2) Find the area of the semicircle

Divide 8 by 2 to find the radius and solve for the area of the circle. Divide this by 2 to represent the semicircle.
3) Subtract the area of the semicircle from the area of the rectangle

I hope this helps!