PQ = PR thus QPR is a in isosceles triangle with < PQR = < PRQ
QR is a the diameter
< QPR = 90 degrees because angle subtended by diameter to a point on the circumference is 90 degrees
< PQR = < PRQ = (180 - 90)/2 = 45 degrees
QR = sqrt( PQ^2 + PR^2) = sqrt( 7^2 + 7^2) = 7sqrt(2)
area of triangle PQR = (1/2)PQ*PR since < P is 90 degrees
= 49/2
area of semi circle is (pi/2)r^2 where r = QR = 7sqrt(2)
= (22/14)*49*2 = 154
area of shaded area = area of semi circle - area of triangle = 154 - 49/2 = 154 - 24.5 = 129.5 sq cm
