The Pythagorean theorem states:
[tex]c^2=a^2+b^2[/tex]
where a and b are the legs and c is the hypotenuse of a right triangle.
Substituting with c = 9 and a = 5, we get:
[tex]\begin{gathered} 9^2=5^2+b^2 \\ 81=25+b^2 \\ 81-25=b^2 \\ 56=b^2 \\ \sqrt[]{56}=b \\ \sqrt[]{4\cdot14}=b \\ \sqrt[]{4}\cdot\sqrt[]{14}=b \\ 2\sqrt[]{14}=b \end{gathered}[/tex]
