# math

posted by
**cole**
.

What polygon has 20 diagonals?I don't know how to figur this out.

THANKS!!!!

A rectangle (4 sides) has 2 diagonals.

A hexagon (6 sides) has 3 diagonals.

An octagon (8 sides) has 4 diagonals.

A _____ (20 sides) has 20 diagonals.