ABCD is a given rectangle with length as 80 cm and breadth as 60 cm. P, Q, R, S are the mid points of sides AB, BC, CD, DA respectively. A circular rangoli of radius 10 cm is drawn at the centre as shown in Fig. 9.69. Find the area of shaded portion.

Area of shaded portion = 4700 cm².
Area of rectangle = 4800. Subtract circle = 314. Remaining ≈ 4700.