Question

In the figure, l(AB) = 14 cm. If the diameters of the semicircles AM and MB are equal, what is the total area of the shaded part?

Answer 1

Diameter of the semicircle AM = Diameter of the semicircle MB = $\frac{l\left(\mathrm{AB}\right)}{2}$ = 7 cm
Radius of both the semicircles = 3.5 cm
Area of a circle = πr²
Total area of the shaded part = Area of the semicircle with AM as diameter + Area of the semicircle with MB as diameter
$=\frac{\mathrm{\pi }\times 3.5\mathrm{cm}\times 3.5\mathrm{cm}}{2}+\frac{\mathrm{\pi }\times 3.5\mathrm{cm}\times 3.5\mathrm{cm}}{2}$
= 38.5 sq cm
∴ Total area of the shaded part is 38.5 sq cm.