 # Animation: The Sum of the Interior Angles of a Triangle

Welcome to an animation, showing the sum of the
interior angles of a triangle The goal of the video is to illustrate the sum interior
angles of any triangle is 180 degrees So, let’s start with this green triangle. I’ll do is find the midpoints of side AB and AC plotted here, then we’ll connect the midpoint to form the midsegment now we’ll form two segment
perpendicular to side BC from these to end points now we can fold angle A across this segment. Now, we’ll fold angle B across this segment. So, In Red we have angle A and angle B and then last, we will fold angle C across this segment and what we can see is that angles A, B, and C form a straight angle which has a measure of 180
degrees it doesn’t matter if we change the triangle
that we have result will still be three angles that form a straight angle which verifies that the sum of the interior angle at any triangle will be 180 degrees I hope you found this illustration helpful

#### One Comment

• The King of Poland says:

SOUND???