In Fig.15.69, AB and CD are two diameters of a circle perpendicular to each other and OD is the diameter of the smaller circle. If OA=7cm, find the area of the shaded region.
Area of semicircle ACB = 
= area of circle with diameter OD = πr2
)
Remaining shaded portion in lower semi circle = 77 – 38.5 = 38.5cm2
Total shaded portion area = 77 + 38.5 = 115.5 cm2
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