SOLUTION: A triangle has these sides. Will it be acute, right, obtuse or not possible? Show work to justify your answers. 1. 5,8,9 2. 3,4,5 3. 3,5,11 4. 2,12,13

Question 688521: A triangle has these sides. Will it be acute, right, obtuse or not possible? Show work to justify your answers.
1. 5,8,9
2. 3,4,5
3. 3,5,11
4. 2,12,13
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
A triangle has these sides. Will it be acute, right, obtuse or not possible? Show work to justify your answers.
1. 5,8,9
2. 3,4,5
3. 3,5,11
4. 2,12,13
Call the longest side c, the others are a & b
If c >= a+b, it's not a triangle
If c <= |a-b| it's not a triangle
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If the square of the longest side < sum of the squares of the other 2, it's acute.
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If the square of the longest side = sum of the squares of the other 2, it's a right triangle.
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If the square of the longest side > sum of the squares of the other 2, it's obtuse.
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