Biconditional Statements for Obtuse Angle and Pentagon Definitions

1. An obtuse angle is defined as an angle that measures greater than 90 degrees if and only if it is not acute.

(Obtuse angle → Angle measures greater than 90 degrees) ∧ (Angle is not acute → Obtuse angle)

2. A pentagon is defined as a polygon with five sides if and only if it is not a polygon with any other number of sides.

(Pentagon → Polygon with five sides) ∧ (Not a polygon with any other number of sides → Pentagon)