If Figure, there are three semicircles, A, B and C having diameter 3cm each, and another semicircle E having a circle D with diameter 4.5cm are shown. Calculate: the area of the shaded region. the cost of painting the shaded region at the rate of 25 paise per `c m^2` , to the nearest rupee.

Explanation

Area of shaded region = Area of larger semicircle - Area of circle with center D - 2(Area of small semi-circle) + Area of small semi-circle

`:.`Area of shaded region = Area of larger semicircle - Area of circle with center D - Area of small semi-circle

Area of shaded region = `( 1/2 xx pi xx (4.5)^2) - (1/2 xx pi xx ((4.5)/2)^2) - ( (1/2 xx pi xx (3/2)^2 `

`:.`Area of shaded region = `pi xx 3.9375= 22/7 xx 3.9375 = 12.375 cm^2`

Cost of painting = `(12.375 xx 0.25) ~= Rs.3`