56.52=3.14*r^2

Solution for 56.52=3.14*r^2 equation:

Simplifying
56.52 = 3.14r2

Solving
56.52 = 3.14r2

Solving for variable 'r'.

Move all terms containing r to the left, all other terms to the right.

Add '-3.14r2' to each side of the equation.
56.52 + -3.14r2 = 3.14r2 + -3.14r2

Combine like terms: 3.14r2 + -3.14r2 = 0.00
56.52 + -3.14r2 = 0.00

Add '-56.52' to each side of the equation.
56.52 + -56.52 + -3.14r2 = 0.00 + -56.52

Combine like terms: 56.52 + -56.52 = 0.00
0.00 + -3.14r2 = 0.00 + -56.52
-3.14r2 = 0.00 + -56.52

Combine like terms: 0.00 + -56.52 = -56.52
-3.14r2 = -56.52

Divide each side by '-3.14'.
r2 = 18

Simplifying
r2 = 18

Take the square root of each side:
r = {-4.242640687, 4.242640687}