SOLUTION: I need help with this proof. I can't get past the given. Given: Triangle RST is an obtuse traingle. Prove: Triangle RST Does not have a right angle.

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Question 554901: I need help with this proof. I can't get past the given.
Given: Triangle RST is an obtuse traingle.
Prove: Triangle RST Does not have a right angle.

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Assume that, on the contrary, triangle RST has a right angle. Then it must have a right angle and an obtuse angle. The sum of these two angles would have to be greater than 180 (90 plus a number greater than 90), which implies a contradiction. Hence RST cannot have any right angles.