Introduction
Determining the Range of the Length of the Third Side of a Triangle

a building with triangular architecture Consider the given information about △ABC.

In △ABC, AB = 8 inches and BC = 9 inches.

What are the possible lengths for the third side of the triangle? Is there only one length that will fit to complete this triangle? Or are there multiple lengths that would work? In this module, you will learn how to determine the answer to this question and many more like it.

Essential Questions

 

Warm-Up

What's the Missing Side? interactivity

warm-up icon In this non-graded interactivity, test your knowledge about determining possible lengths for the third side of a triangle. Click the player button to get started.