Question

Explain the parallel and perpendicular therom

Answer 1

parallel axis theorem

moment of inertia along a axis parallel to another axis is ( MOI of that axis + mr^2) where r is distance of parallel axis from that axis

perpendicular axis theorem

if you know the Moi of two perpendicular axis then
then Moi of axis perpendicular to both equal to sum of there MOI
Iz =Ix + Iy