what is the formula for finding the number of diagonals in a polygon? Share with your friends Share 0 Abhishek Kr. Jha answered this Here is the link for the answer to your query. https://www.meritnation.com/ask-answer/question/how-can-we-find-that-how-many-diagonals-are-there-in-the-giv/understanding-quadrilaterals/1281456 1 View Full Answer Shubha answered this The number of diagonals in a polygon of 'n' sides = n(n-3)/2 3