a) The area of the shaded region is 50π.
b)

Explanation:
Step 1:
The area of a circle

The area of a semi-circle

The area of a quarter-circle

The shaded region's area is obtained by subtracting the area of the semi-circle with a radius of 10 cm from the area of a quarter-circle with a radius of 20 cm.
The area of the semi-circle with a radius of 10 cm

The area of the quarter-circle with a radius of 20 cm

Step 2:
The area of the shaded region is obtained by subtracting these areas.
The area of the shaded region




The area of the shaded region is 50π square units.
Step 3:
The area of a square is the square of the side length.
The area of the square
square cm.
b)
