Introduction

Students often want to know if they will ever use the math concepts they are learning in school. It’s a good question. The angle relationships in a triangle are a good example of how these concepts are useful in real-world applications. Did you know that the theorem for the interior angles of a triangle is how your phone’s GPS locates you?

Students often want to know when they will ever use math concepts they are required to learn. Today we will focus on the angle relationships in any triangle.

Go to ACCESS - Sum of Angles in a Triangle. Notice what the sum of the interior angles equal.

Then, go to ACCESS - Exterior Angles. Also do you notice anything about the sum of two of the interior angles?

Download and complete 4.04 Explore. When you have finished, submit it to the 4.04 Explore Dropbox.

 

Lesson Objectives

Following successful completion of this lesson, students will be able to...

  • Use angle addition theorem to solve problems with triangles.
  • Identify and use the exterior angle theorem of a triangle
  • Prove theorems about triangles.

Enduring Understandings

  • The sum of the interior angles of any triangle is a constant.

The above objectives correspond with the Alabama Course of Study: Geometry standards: Geometry Standards: 10.

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