X2 + (A + B)2 = (A + 2B – X)2
X2 + A2 + 2AB + B2 = A2 + B2 + X2 + 4AB - 2AX -4BX
2AB - 2AX –4BX = 0
X(2A + 4B) = 2AB
X = AB/(A+2B)
Sin2@ = (A+B)/(A + 2B – X)
Sin@/X = Sin(180 – 2@) / A
= 2sin(90 - @) cos (90 - @) / A
= 2sin@cos@ / A
= sin2@/A
sin@ = X(A+B)/A(A + 2B – X)...