In the figure 7.46, if O is the centre of the circle, PQ is a chord. POQ = 90°, area of shaded region is 114 cm2 , find the radius of the circle. ( = 3.14)

Given POQ = = 90°,
area of shaded region PRQ = 114cm²
Area of segment PRQ = r²[(/360) – (sin/2)]
114 = r²[3.14×90/360 – sin90˚/2]
114 = r²[3.14×(1/4) – 1/2]
114 = r²[0.785-0.5]
114 = r²×0.285
r² = 114/0.285 = 400
Taking square root on both sides
r = 20cm
Hence the radius of the circle is 20cm.