Question

What is the moment of inertia of a circular ring of radius R and mass M about a tangent in its plane ?

Answer 1

$iz = ix + iy \\ m {r}^{2} = ix + ix \\ ix = m {r}^{2} \div 2 \\ where \: ix = mof \: along \: diameter \\ by \:parallel \: theorem \\ mof \: about \: tangent = 3m {r}^{2} \div 2$