Answer:
Part 1)

Part 2)

Part 3)

Part 4)

Part 5)

Part 6)

Explanation:
Part 1) we know that
The shaded region is equal to the area of the complete rectangle minus the area of the interior rectangle
The area of rectangle is equal to

where
b is the base of rectangle
h is the height of rectangle
so

Part 2) we know that
The shaded region is equal to the area of the complete rectangle minus the area of the interior square
The area of square is equal to

where
b is the length side of the square
so

Part 3) we know that
The area of the shaded region is equal to the area of four rectangles plus the area of one square
so

Part 4) we know that
The shaded region is equal to the area of the complete square minus the area of the interior square
so

Part 5) we know that
The area of the shaded region is equal to the area of triangle minus the area of rectangle
The area of triangle is equal to

where
b is the base of triangle
h is the height of triangle
so

Part 6) we know that
The area of the shaded region is equal to the area of the circle minus the area of rectangle
The area of the circle is equal to

where
r is the radius of the circle
so
