Interior and Exterior Angles Exploration

INSTRUCTIONS

Experiment with the sliders and answer the questions along the way.[br]You can also move the vertices (white dots) to change the shape of each Triangle.[br]Have fun!

Triangle

Interior angles in a Triangle

Move the slider "Show Interior Angles" slowly and watch what happens.[br]What is the best description of the angle that is created by the sum of these angles?

It is a right angle None of the above It is a full circle it is a half circle

Interior angles in a Triangle

Move the slider "Show Interior Angles" slowly and watch what happens.[br]What is the sum of the interior angles in any triangle?[br]You can change the shape of the triangle by moving vertices.

[math]180^o[/math] [math]360^o[/math] [math]270^o[/math] [math]90^o[/math]

Interior Angles - Explanation

Justify your answer to the above question, how do you know from the applet?

Exterior Angles in a Triangle

Now play with the slider "Show Exterior Angles" and notice what happens when you slide it all the way to the right side.[br]What is the best description for the sum of the exterior angles?

It is a right angle or [math]90^o[/math] It is a full circle or [math]360^o[/math] It is the same as the sum of interior angles = [math]180^o[/math] It is [math]\frac{3}{4}[/math] of a circle or [math]270^o[/math]

Exterior Angle Theorem The two colored angles are said to be the "remote interior" angles from the labeled exterior angle. What do you think the definition of remote interior angle is?

When you moved the slider, the two remote interior angles moved. What did you notice that happened? What do you think the Exterior Angle Theorem is?

Interior and Exterior Angles Exploration

INSTRUCTIONS

Triangle

Interior angles in a Triangle

Interior angles in a Triangle

Interior Angles - Explanation

Exterior Angles in a Triangle

Information: Interior and Exterior Angles Exploration