In Fig. 12.25, ABCD is a square of side 14 cm. With centers A, B, C and D, four circles are drawn such that each circle touch externally two of the remaining three circles. Find the area of the shaded region.
Area of each of the 4 sectors is equal to each other and is a sector of 90° in a circle of 7 cm radius
Area of each sector = 
* 
(7)2
= 
* 
* 7 * 7
= 
cm2
Area of square ABCD = (Side)2
= (14)2
= 196 cm2
Area of shaded portion = Area of square ABCD - 4 × Area of each sector
= 196 – 4 * 
= 196 – 154
= 42 cm2
Therefore, the area of shaded portion is 42 cm2
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