## Precalculus (10th Edition)

$7517.38$ square feet
By Heron's formula, $K=\sqrt{s(s-a)(s-b)(s-c)}$, where $s=\frac{a+b+c}{2}.$ Hence, here we have $s=\frac{87+190+173}{2}=225$, Thus, $K=\sqrt{225(225-87)(225-190)(225-173)}\approx7,517.38$ square feet