3.14(r^2)=153.86

Solution for 3.14(r^2)=153.86 equation:

3.14(r^2)=153.86

We move all terms to the left:

3.14(r^2)-(153.86)=0

We add all the numbers together, and all the variables

3.14r^2-153.86=0

a = 3.14; b = 0; c = -153.86;
Δ = b2-4ac
Δ = 02-4·3.14·(-153.86)
Δ = 1932.4816
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{1932.4816}}{2*3.14}=\frac{0-\sqrt{1932.4816}}{6.28}
=-\frac{\sqrt{}}{6.28}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{1932.4816}}{2*3.14}=\frac{0+\sqrt{1932.4816}}{6.28}
=\frac{\sqrt{}}{6.28}
$