(a)Find an expression for the exact perimeter, P, of the region. P = (b) Find an expression for the exact area, A, of the region.

Question

For the semicircular region shaded, the length of the radius is r.

A circle has its center at point Q.

1. A diameter is horizontal. It starts at point C on the left, goes through point Q and ends at point D on the right.
2. The area above the diameter in the interior of the circle is shaded.

(a)Find an expression for the exact perimeter, P, of the region.

P = 

 

(b) Find an expression for the exact area, A, of the region.

Answer 1

The perimeter is pi*r + 2r.

The area is (1/2)pi*r².