we have
find a, we used the pythagorean theorem, this is:
[tex]\begin{gathered} a^2+b^2=c^2 \\ a^2+(21.5)^2=(31.9)^2 \\ a^2+462.25=1017.61 \\ a^2+462.25-462.25=1017.61-462.25 \\ a^2=555.36 \\ a=\sqrt[]{555.36} \\ a=23.6 \end{gathered}[/tex]answer: a is approximately 23.6 inches
