### Proof By Disproving all other Angles

Proof that the total of the degrees cannot exceed 180 or go below 180

Here is a right triangle with the two adjacent sides both being three units long

As you can see the line off the 50 degree angle at c does not meet up with the endpoint of line C (And if you extended line C then the angle at the top would no longer be 45 degrees but 40 degrees. So it would still be a 180 degree figure). This would be true for any angle above 180 degrees. Then when it is below 180 degrees line B cuts through line C instead of meeting it at the endpoint. The angle where that meets it ends up being b – c = a (Assuming that you had b as the largest angle). Then if you input any of those into the formula a + b + c = 180 it works. (b – c) + b + c = 180 then you input the largest angle for b any angle for c that doesn't bring the total to 180 into that formula and you will get 180 unless your angle b is 180 or greater or sixty or less (sixty or less and b is not the greatest angle). Then you get a closed figure with three angles, a triangle. If you put anything greater than 180 for the total you get something like 180 = 181. You put something less than 180 than you get something like 180 = 179 which is completely wrong. So by proving that the angles in a triangle cannot be anything greater than 180 degrees or less than 180 degrees and that 180 degrees works, we can state that all triangles have 180 degrees.

## 5 Comments:

I think a diagram is missing?

i think blogger is deviously working against me, because it won't upload my image and it doesn't like my preformatted text

nevermind blogger just doesn't like my mothers computer. The picture uploads just fine on a different computer.

Graeme, we know that a + b = d

BECAUSEthere are 180 degrees in a triangle -- you have to prove that fact before you can use it.Nonetheless, I'm impressed with your effort -- you're the first person who has tried to prove it without looking it up on the internet. ;-)

Well is this correct now Mr. Kuropatwa?

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