6586.5896=4*3.14r^2

Solution for 6586.5896=4*3.14r^2 equation:

Simplifying
6586.5896 = 4 * 3.14r2

Multiply 4 * 3.14
6586.5896 = 12.56r2

Solving
6586.5896 = 12.56r2

Solving for variable 'r'.

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

Add '-12.56r2' to each side of the equation.
6586.5896 + -12.56r2 = 12.56r2 + -12.56r2

Combine like terms: 12.56r2 + -12.56r2 = 0.00
6586.5896 + -12.56r2 = 0.00

Add '-6586.5896' to each side of the equation.
6586.5896 + -6586.5896 + -12.56r2 = 0.00 + -6586.5896

Combine like terms: 6586.5896 + -6586.5896 = 0.0000
0.0000 + -12.56r2 = 0.00 + -6586.5896
-12.56r2 = 0.00 + -6586.5896

Combine like terms: 0.00 + -6586.5896 = -6586.5896
-12.56r2 = -6586.5896

Divide each side by '-12.56'.
r2 = 524.41

Simplifying
r2 = 524.41

Take the square root of each side:
r = {-22.9, 22.9}