Two masses m and M are attached with strings as shown. For the system to be in equilibrium, we have
tanθ = 1 + 2Mm
tanθ = 1 + 2mM
tanθ = 1 + M2m
tanθ = 1 + m2M
2T1 cos 450 = mg
∴ T1 = mg2
T2 cosθ = T12 = mg2
T2 sinθ = Mg+mg2
tanθ = Mg+mg2mg2 = 1+2Mm