From a semicircular disc of radius `r_(1)`, another semicircular disc of radius `r_(2)` is removed. Find the `c.m.` of the remaining position.

From a disc of radius r_(1) , a concentric disc of radius r_(2) is removed . The mass of the remaining portion is m . Find the M.I. of the remaining about an axis passing through the center of mass and perpendicular to the plane.

From a circular disc of radius R , another disc of diameter R is removed. Locate c.m. of the remaining portion.

From a disc of mass m and radius r , a circular portion of radius (r )/(3) is removed from the edges. Find the M.O.I of the remaining system about a normal through center of original disc

From a circular disc of radius R and mass 9 M , a small disc of radius R/3 is removed from the disc. The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and passing through O is

A semicircular disc has a radius of 21 cm. Find its perimeter.