125^2=3.14r^2

Solution for 125^2=3.14r^2 equation:

125^2=3.14r^2

We move all terms to the left:

125^2-(3.14r^2)=0

We add all the numbers together, and all the variables

-(3.14r^2)+15625=0

We get rid of parentheses

-3.14r^2+15625=0

a = -3.14; b = 0; c = +15625;
Δ = b2-4ac
Δ = 02-4·(-3.14)·15625
Δ = 196250
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{196250}=\sqrt{625*314}=\sqrt{625}*\sqrt{314}=25\sqrt{314}$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-25\sqrt{314}}{2*-3.14}=\frac{0-25\sqrt{314}}{-6.28}
=-\frac{25\sqrt{314}}{-6.28}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+25\sqrt{314}}{2*-3.14}=\frac{0+25\sqrt{314}}{-6.28}
=\frac{25\sqrt{314}}{-6.28}
$