Question 694548: A right triangle has a perimeter of 36 units if the hypotenuse is 15 units, how long are the other 2 sides?
can you please explain me this? I dont understand.Thanks in advance.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A right triangle has a perimeter of 36 units if the hypotenuse is 15 units, how long are the other 2 sides?
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Perimeter = a + b + c
36 = a + b + 15
a + b = 21
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a = 21-b
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Use Pythagoras:
a^2 + b^2 = c^2
(21-b)^2 + b^2 = 15^2
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441 - 42b + 2b^2 = 225
2b^2 - 42b + 216 = 0
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b^2 -21b + 108 = 0
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b = [21 +- sqrt(441-4*108)]/2
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b = [21 +- sqrt(9)]/2
b = [21+- 3]/2
b = 12 or b = 9
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Using a = 21-b
If b = 12, a = 9
If b = 9, a = 12
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cheers,
Stan H.
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