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One leg of a right angel is 4 less than the other leg. The square of the hypotenuse of the right angel is 80. How long are the legs of the right triangle? Show your work.

1 Answer

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Sometimes these problems are easier to work if you consider the average of the two leg lengths. Call that "x".
.. (x -2)^2 +(x +2)^2 = 80 . . . . . . . by the Pythagorean theorem
.. x^2 -4x +4 +x^2 +4x +4 = 80 . . eliminate parentheses
.. 2x^2 +8 = 80 . . . . . . . . . . . . . . . simplify
.. x^2 = (80 -8)/2 = 36
.. x = √36 = 6
Legs are this value ±2.

The leg lengths are 4 and 8.
User Lii
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