A pentagon has exactly 5 sides. Prove the following conditional by proving the contrapositive. If a polygon does not have exactly five sides, then it is not a pentagon.

does not have five sides
true

has five sides

polygon

hexagon

false

pentagon

Contrapositive: If a is a then the .
Since a pentagon has exactly 5 sides, the contra positive is . Since the contrapositive is , the original statement must be