SOLUTION: Use indirect reasoning to explain why an obtuse triangle cannot have a right angle This is a take home test question.

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Question 181206: Use indirect reasoning to explain why an obtuse triangle cannot have a right angle
This is a take home test question.
Answer by Mathtut(3670) About Me  (Show Source):
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Identify the conjecture to be proven.
Given: ABC is an obtuse ,
B is an obtuse angle;
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Prove: ABC does not have a right angle.
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2. Assume the opposite of the conclusion. Write this assumption.Assume ABC does have a right angle. Let A be a right angle.
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3. Use direct reasoning to arrive at a contradiction. Possible answer: If A is a right angle, then measurement of angle B + angle C =90°. But angle B is > 90°, since B is obtuse. So this is a contradiction.
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4. What can you conclude? The assumption that ABC does have a right angle is false. Therefore ABC does not have a right angle. .