Concept

Obtuse Angle

An obtuse angle is an angle whose measure is greater than 90^(∘) but less than 180^(∘).

Applet showing when an angle is acute and when it is not.

When using radians as the unit of measure, an angle is obtuse when its measure is greater than π2, or about 1.57, but less than π, or about 3.14, radians.

Exercises
Edit Lesson