Question

The number of diagonals that can be drawn by joining the verticles of an octagon is

• A. 20
• B. 28
• C. 8
• D. 16

Answer 1

The correct option is A

20

An octagon has 8 vertices.

The number of diagonals of a polygon is given by $\frac{n(n-3)}{2}$

$\therefore$ Number of diagonals of an octagon

$=\frac{8(8-3)}{2}=20$