Consider regular polygons with number of sides n=3,4,5....... as shown in the figure. The center of mass of all the polygons is at height h from the ground. They roll on a horizontal surface about the leading vertex without slipping and sliding as depicted. The maximum increase in height of the locus of the center of mass for each polygon is Δ. Then Δ depends on n and h as
Δ=h(1cos(πn)−1)
Let n be the number of sides of a regular polygon . By symmmetry, its centre of mass O will be at same distance from each vertex.
Let r be the radius of circumscribed circle and h be the perpendicular distance of O from any side. The angle subtended by any side on the centre
O is 2πn and so half of the angle subtended ∠POQ=πn
Here when the polygon rolls without slipping or sliding about the point P, the point O moves with the circle of radius r about the point P. The point O reaches the maximum height
(point O′ in the figure) when PO′ is perpendicular to PQ. Thus, the maximum increase in height of the locus of the centre of mass O is given by
Δ=r−h=hcos(πn)−h=h(1cos(πn)−1)