Find the area of the shaded region in Fig. 12.19, if PQ = 24 cm, PR = 7 cm and O is the centre of the circle.
Here, OR is the hypotenuse of as lines from two ends of diameter always make a right angle when they meet at the circumference of that circle.
Hence,
OR2 = PQ2 + PR2
OR2 = 242 + 72
OR2 = 576 + 49
OR = 25 cm
Or, radius = 12.5cm
Area of triangle = 1/2 * base *height
= 1/2 * 24 *7
Area of semicircle = 2
= 2
= 245.3125 sq cm
Hence,
Area of shaded region = 245.3125 – 84
= 161.3125 sq cm