Work Shown:
[tex]a^2 + b^2 = c^2\\\\x^2 + 84^2 = 91^2\\\\x^2 + 7056 = 8181\\\\x^2 = 8181-7056\\\\x^2 = 1225\\\\x = \sqrt{1225}\\\\x = 35[/tex]
Side note: Since all sides of this right triangle are integers, this means we have a pythagorean triple. The triple 35-84-91 is based off the 5-12-13 right triangle. Divide all sides of 35-84-91 by the GCF 7 to end up with 5-12-13.
