1=4*3.14*x^2

Solution for 1=4*3.14*x^2 equation:

Simplifying
1 = 4 * 3.14x2

Multiply 4 * 3.14
1 = 12.56x2

Solving
1 = 12.56x2

Solving for variable 'x'.

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

Add '-12.56x2' to each side of the equation.
1 + -12.56x2 = 12.56x2 + -12.56x2

Combine like terms: 12.56x2 + -12.56x2 = 0.00
1 + -12.56x2 = 0.00

Add '-1' to each side of the equation.
1 + -1 + -12.56x2 = 0.00 + -1

Combine like terms: 1 + -1 = 0
0 + -12.56x2 = 0.00 + -1
-12.56x2 = 0.00 + -1

Combine like terms: 0.00 + -1 = -1
-12.56x2 = -1

Divide each side by '-12.56'.
x2 = 0.07961783439

Simplifying
x2 = 0.07961783439

Take the square root of each side:
x = {-0.282166324, 0.282166324}