498.5064=4*3.14*r^2

Solution for 498.5064=4*3.14*r^2 equation:

Simplifying
498.5064 = 4 * 3.14r2

Multiply 4 * 3.14
498.5064 = 12.56r2

Solving
498.5064 = 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.
498.5064 + -12.56r2 = 12.56r2 + -12.56r2

Combine like terms: 12.56r2 + -12.56r2 = 0.00
498.5064 + -12.56r2 = 0.00

Add '-498.5064' to each side of the equation.
498.5064 + -498.5064 + -12.56r2 = 0.00 + -498.5064

Combine like terms: 498.5064 + -498.5064 = 0.0000
0.0000 + -12.56r2 = 0.00 + -498.5064
-12.56r2 = 0.00 + -498.5064

Combine like terms: 0.00 + -498.5064 = -498.5064
-12.56r2 = -498.5064

Divide each side by '-12.56'.
r2 = 39.69

Simplifying
r2 = 39.69

Take the square root of each side:
r = {-6.3, 6.3}