A B C is a plane lamina of the shape of an equilateral triangle. D ,   E are mid-points of A B ,  …
is a plane lamina of the shape of an equilateral triangle. are mid-points of and is the centroid of the lamina. Moment of inertia of the lamina about an axis passing through and perpendicular to the plane is . If part is removed, the moment of inertia of the remaining part about the same axis is where is an integer. Value of is:
Solution
Let mass of lamina , and length of side , then moment of inertila of lamina about an axis passing through and perpendicular to the plane.