Question

Four equal circles, each of radius 5 cm, touch each other as shown in Fig. 20. Find the area included between them. (Take π = 3.14).

Answer 1

Side of the square = 10 cm
Area of the square = Side $\times$ Side
Area of the square = ^{$10\times 10=100{\mathrm{cm}}^2$}

Area of the four quarter circles = ^{$4\times \frac{1}{4}\times \frac{22}{7}\times 5^2=78.57{\mathrm{cm}}^2$}
Area included in them = Area of the square - Area of the four quarter circles
Area included in them = ( 100 - 78.57 ) cm² = 21.43 cm² .