A semi-circular arch section has an outer radius of 3 m and an inner radius of 2 m. What is the moment of inertia of this section about its base diameter AB?

Determine the mass moment of inertia of three identical uniform rods (each of mass m and length l) arranged to form an equilateral triangle, about an axis perpendicular to the plane of the triangle and passing through its centroid.

Determine the mass moment of inertia of three identical rods (each of mass m and length l) arranged to form an equilateral triangle, about an axis perpendicular to the plane of the triangle and passing through its centroid.