Operating on the triangle. using a straightedge, draw a random triangle. now carefully cut it out. next amputate the angles by s
nipping through adjacent sides. now move the angles together so the verticles all touch and the edges meet. what do you conclude about the sum of the angles of a triangle?
The sum of the measures of the angles in a triangle is always 180 degrees.
If you follow the procedure in the question, you will have a straight angle when you put the pieces together. All straight angles have 180 degrees. Therefore, there are 180 degrees in every triangle.