52=3.14r^2

Solution for 52=3.14r^2 equation:

Simplifying
52 = 3.14r2

Solving
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.
52 + -3.14r2 = 3.14r2 + -3.14r2

Combine like terms: 3.14r2 + -3.14r2 = 0.00
52 + -3.14r2 = 0.00

Add '-52' to each side of the equation.
52 + -52 + -3.14r2 = 0.00 + -52

Combine like terms: 52 + -52 = 0
0 + -3.14r2 = 0.00 + -52
-3.14r2 = 0.00 + -52

Combine like terms: 0.00 + -52 = -52
-3.14r2 = -52

Divide each side by '-3.14'.
r2 = 16.56050955

Simplifying
r2 = 16.56050955

Take the square root of each side:
r = {-4.069460597, 4.069460597}