Question

Find the number of triangles which can be formed by joining the angular points of a polygon of 8 sides as vertices.

(A) 16

(B) 56

(C) 24

(D) 8

Answer 1

(B) 56

A triangle is obtained by joining three vertices. Number of ways of selecting 3 vertices out of 8 vertices = ⁸C₃

\(=\frac{8\times7\times6}{1\times2\times3}\) = 56