QR = ST = 480...eqn 1
CU = 5x...eqn 2
CV = 9x -56...eqn 3
CR = CT = radius of circle
UR = O.5 QR
VT = 0.5 ST
from eqn 1...UR = VT
=> UR = VT
thus CU = CV
Subs eqn 1 into eqn 2
=> 9x -56 = 5x
=> x = 14
=> CV = 9(14) - 56 = 70 = CU
Using a^2 + b^2 = c^2
=> c^2 = 70^2 + 240^2
=> c^2 = 4900 + 57600 = 62500
=> c = 250
radius of circle is 250
