If Z is the circumcenter of triangle QRS find each measureQR=RZ=XS=ZS=WZ=
QR = 2*QW = 2*25 = 50
RZ = sqrt ( RX^2 + ZX^2 ) = sqrt ( 40^2 + 9^2) = sqrt ( 1681) = 41
XS = RX = 40
ZS = RZ = 41
WZ = sqrt ( RZ^2 - RW^2) = sqrt ( 41^2 - 25^2) =
sqrt ( 1681 - 625) = sqrt (1056) = 4sqrt (66) ≈ 32.5
