Let x represent the length of the shorter leg.
Longer leg: 5x +19
Hypotenuse: 5x +20
Pythagorean theorem:
.. x^2 +(5x +19)^2 = (5x +20)^2
.. x^2 +25x^2 +190x +19^2 = 25x^2 +200x +20^2 . . . . . . eliminate parentheses
.. x^2 -10x -39 = 0
.. (x -13)(x +3) = 0
.. x = 13 . . . . . . . . . . leg lengths must be positive
The side length of the triangle are 13, 84, 85 feet.
