The Pythagorean theorem states:
[tex]c^2=a^2+b^2[/tex]
where a and b are the lengths of the legs and c is the length of the hypotenuse of a right triangle.
Substituting with a = 80 and b = 39, we get:
[tex]\begin{gathered} c^2=80^2+39^2 \\ c^2=6400+1521 \\ c^2=7921 \\ c=\sqrt[]{7921} \\ c=89 \end{gathered}[/tex]
