Question
The measure of an angle in degrees, grades and radians be D, G and C respectively, then relation between them D90=G100=2Cπ but 1∘=(180π)∘≃57∘,17′,44.8′′ and sum of interior angles of a n-sided regular polygon is (2n−4)π2. On the basis of above information, answer the following questions :The number of sides of two regular polygon are as 5 : 4 and the difference between their angles is π20, then the number of sides in the polygons respectively are -