Question

Explain why sum of all angles of triangle is 180

Answer 1

Step-by-step explanation:

In short, the interior angles are all the angles within the bounds of the triangle. ... If you think about it, you'll see that when you add any of the interior angles of a triangle to its neighboring exterior angle, you always get 1800—a straight line.May

Answer 2

Answer:

1) Draw a line parallel to one of the sides of the triangle that passes through the corner opposite to that side:

2) This creates two new angles. We’ll call them D and E:

3) We know by Alternate Interior Angles that angle D must be the same as angle A and angle E must be the same as angle C.

4) Replace the new angles found in step 2) with Aand C:

5) We see that angle A + angle B + angle C add up to give us a straight line or 180°: