# Classifying Triangles

- Draw a triangle consisting of side lengths of the 3, 4, and 5 inches. “How would you classify the largest angle in this triangle?”
- How can you verify if a triangle has a right angle, and is therefore, a right triangle? (Note: One way to verify that a triangle has a right angle is to use a protractor.)
- How could you test to see if a triangle is acute or obtuse?

Watch the following video to see how to use the side lengths to classify triangles by angle.

Using the Pythagorean Theorem to classify triangles.