Answer:
we know,
area of circle = πr²
area of semicircle of circle having diameter of 16.
according to formula = πr²
radius = 16/2 = 8 cm
22/7 × (8)² → 22/7 × 64 → 1408/7 = 201.14/2 = 100.57 cm (approx.)
area of semicircle of circle having diameter of 20 cm.
22/7 × 20² = 22/7 × 400 = 8800/7 = 1257.14/2 = 628.57
to get the area of shaded part 628.57 - 100.57 = 528 cm² (approx.)
hope this helps you!