Answer
Yes
Work Step by Step
You have to use the Pythagorean theorem to determine if this is a right triangle.
A=18, B=52.5, C=55.5:
$a^{2}$+$b^{2}$=$c^{2}$
$18^{2}$+$52.5^{2}$=$55.5^{2}$ -simplify the exponents-
32.4+2756.25=3080.25 -simplify like terms-
3080.25=3080.25
They are equal so yes this is a right triangle.
