Triangle Sum Theorem

Zach Longo


1. Click and drag the vertices of the triangle to create different angles for angle A, angle B, and angle C.  2. Fill in the angles for each in the table below and find the sum of the angles in the last column. 3. What do you observe about the sum of the three angles within a triangle no matter what they are set to? 4. Click and drag the sliders to rotate the vertices. 5. Draw the result 6. What do you observe about the triangle's three interior angles when the sliders are set to 180?