216^2+90^2=c^2

Solution for 216^2+90^2=c^2 equation:

216^2+90^2=c^2

We move all terms to the left:

216^2+90^2-(c^2)=0

We add all the numbers together, and all the variables

-1c^2+54756=0

a = -1; b = 0; c = +54756;
Δ = b2-4ac
Δ = 02-4·(-1)·54756
Δ = 219024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{219024}=468$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-468}{2*-1}=\frac{-468}{-2}
=+234
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+468}{2*-1}=\frac{468}{-2}
=-234
$