Answer
$90\sqrt 2$ or $127.3$ feet
Work Step by Step
The Pythagorean theorem is $a^2+b^2=c^2$ to solve for the hypotenuse of a right triangle. We are given that two sides are 90 feet.
$90^2+90^2=c^2$
$8100+8100=c^2$
$16200=c^2$
$c=\sqrt {16200}$
$c=90\sqrt 2$
$c\approx127.3$
