How can we locate the centre of mass of rigid bodies of regular geometrical shape and having uniform mass distribution? Give examples.

The center of mass can be found by using the concept of symmetry and geometric principles. For a rectangle, the diagonals cross each other at its center of mass. In the case of a circle or a cylinder, it is located at the middle of the geometric figure. In a solid sphere, it also lies at its center.
For a triangular plate, it lies at the point of intersection of the medians. In regular polygons, it is at the intersection of diagonals or at the centroid of the shape which is obtained by averaging the coordinates of the vertices.