- #1
musicgold
- 304
- 19
Hi,
Please refer to the Pythagorean proof of the theorem that the angels in a triangle add to 180 degrees. The following link has the proof.
http://www.cut-the-knot.org/triangle/pythpar/AnglesInTriangle.shtml
You will note that this proof is based on the assumptions that angles on a straight line add to 180 degrees. But we have no proof of that fact. I mean we can measure it with a protractor, but is there a way to prove that?
So I am wondering about the whole process of proving a theorem. We use some assumptions to prove a statement. The assumptions themselves are theorems that have to proved somewhere else. Is that the right way to think about it?
Thanks.
Please refer to the Pythagorean proof of the theorem that the angels in a triangle add to 180 degrees. The following link has the proof.
http://www.cut-the-knot.org/triangle/pythpar/AnglesInTriangle.shtml
You will note that this proof is based on the assumptions that angles on a straight line add to 180 degrees. But we have no proof of that fact. I mean we can measure it with a protractor, but is there a way to prove that?
So I am wondering about the whole process of proving a theorem. We use some assumptions to prove a statement. The assumptions themselves are theorems that have to proved somewhere else. Is that the right way to think about it?
Thanks.