The shaded regions consist of a triangle and a semicircle
Area of shaded regions = Area of Triangle + Area of semicircle
Area of Triangle = (h x b) ÷ 2
Height, h = 10 cm
Base, b = 8 cm
Are of the triangle component = (10 x 8) ÷ 2
= 80 ÷ 2
= 40 cm^2
Area of semicircle = πr^2 ÷ 2
Diameter, D = 8 cm
Radius, r = 8 cm ÷ 2 = 4 cm
Are of the semicircle component = [π(4^2) ÷ 2)
= 16π ÷ 2
= 16π cm^2
Total area of shaded regions
= (40+16π) cm^2
= 8 (5 +2π) cm^2