CC3 9.1.2: Triangle Angle Sum Theorem (Desmos)
Click on the link below to access eTool
Use this eTool to demonstrate the Triangle Angle Sum Theorem.
1. Click the colored points and drag to change the angles.
NOTE: The measurements for each angle are shown at the left panel.

2. Click the circle at left on line 4 to show wich angles are the same.
