Question

Give a proof that the angles in a triangle add up to 180 degrees.

Answer 1

There is a way to prove this by using limits.

I start on triangle ABC up in the top left, an equilateral triangle.

The next triangle down is what happens when I take angles A and B and make them smaller, and consequently make angle C larger.

The next triangle is a continuation of same process: reduce the angle measures of A and B and increase angle C.

Do this again. Do this again. Do this again until.....

Angles A and B will eventually approach the value of 0°, angle C will obviously approach a straight line, also known as 180°.

Now sum 0, 0, and 180 to arrive at the answer of 180°.

Hence it proved the above statement.