The properties of the interior and exterior angles of triangles are observed.
After completing this tutorial, you will be able to complete the following:
The sum of the interior angles of a triangle equals 180 degrees.
When the three interior angles of any triangle are added together, they will always equal 180 degrees.
A triangle with two transversals and a line parallel to the base of the triangle passing through the other vertex has several equal angles.
An exterior angle of a triangle is equal to the sum of the interior angles at the other two vertices.
In this drawing, let x be the measure of .
So, to find the measure of the exterior angle, add the interior angles at the other two vertices.
The following key vocabulary terms will be used throughout this Activity Object:
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Students should know the angles, corresponding angles, interior and exterior angles, triangles, and vertical angles.|
|Type of Tutorial||Visual Proof|
|Key Vocabulary||angles, exterior angles of a triangle, interior angles of a triangle|