# Classifying Triangles by Interior Angles

In our study of Measurement we learned that we there were numerous different types of angles. For a review click here.

Using this previous knowledge, we can classify triangles by their interior angles. There are three types of angles we can classify this way:

- Right Triangles
- Obtuse Triangles
- Acute Triangles

A right triangle is a triangle with one angle that measures 90° (a right angle).

An obtuse triangle is a triangle that has an angle that is greater than 90°.

An acute triangle is a triangle with only acute interior angles (all angles are smaller than 90°.