18079.179=2*3.14*r^2+2*3.14*r*112.4

Solution for 18079.179=2*3.14*r^2+2*3.14*r*112.4 equation:

Simplifying
18079.179 = 2 * 3.14r2 + 2 * 3.14r * 112.4

Multiply 2 * 3.14
18079.179 = 6.28r2 + 2 * 3.14r * 112.4

Reorder the terms for easier multiplication:
18079.179 = 6.28r2 + 2 * 3.14 * 112.4r

Multiply 2 * 3.14
18079.179 = 6.28r2 + 6.28 * 112.4r

Multiply 6.28 * 112.4
18079.179 = 6.28r2 + 705.872r

Reorder the terms:
18079.179 = 705.872r + 6.28r2

Solving
18079.179 = 705.872r + 6.28r2

Solving for variable 'r'.

Reorder the terms:
18079.179 + -705.872r + -6.28r2 = 705.872r + -705.872r + 6.28r2 + -6.28r2

Combine like terms: 705.872r + -705.872r = 0.000
18079.179 + -705.872r + -6.28r2 = 0.000 + 6.28r2 + -6.28r2
18079.179 + -705.872r + -6.28r2 = 6.28r2 + -6.28r2

Combine like terms: 6.28r2 + -6.28r2 = 0.00
18079.179 + -705.872r + -6.28r2 = 0.00

Begin completing the square.  Divide all terms by
-6.28 the coefficient of the squared term: 

Divide each side by '-6.28'.
-2878.850159 + 112.4r + r2 = 0

Move the constant term to the right:

Add '2878.850159' to each side of the equation.
-2878.850159 + 112.4r + 2878.850159 + r2 = 0 + 2878.850159

Reorder the terms:
-2878.850159 + 2878.850159 + 112.4r + r2 = 0 + 2878.850159

Combine like terms: -2878.850159 + 2878.850159 = 0.000000
0.000000 + 112.4r + r2 = 0 + 2878.850159
112.4r + r2 = 0 + 2878.850159

Combine like terms: 0 + 2878.850159 = 2878.850159
112.4r + r2 = 2878.850159

The r term is 112.4r.  Take half its coefficient (56.2).
Square it (3158.44) and add it to both sides.

Add '3158.44' to each side of the equation.
112.4r + 3158.44 + r2 = 2878.850159 + 3158.44

Reorder the terms:
3158.44 + 112.4r + r2 = 2878.850159 + 3158.44

Combine like terms: 2878.850159 + 3158.44 = 6037.290159
3158.44 + 112.4r + r2 = 6037.290159

Factor a perfect square on the left side:
(r + 56.2)(r + 56.2) = 6037.290159

Calculate the square root of the right side: 77.700001023

Break this problem into two subproblems by setting 
(r + 56.2) equal to 77.700001023 and -77.700001023.

Subproblem 1
r + 56.2 = 77.700001023

Simplifying
r + 56.2 = 77.700001023

Reorder the terms:
56.2 + r = 77.700001023

Solving
56.2 + r = 77.700001023

Solving for variable 'r'.

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

Add '-56.2' to each side of the equation.
56.2 + -56.2 + r = 77.700001023 + -56.2

Combine like terms: 56.2 + -56.2 = 0.0
0.0 + r = 77.700001023 + -56.2
r = 77.700001023 + -56.2

Combine like terms: 77.700001023 + -56.2 = 21.500001023
r = 21.500001023

Simplifying
r = 21.500001023

Subproblem 2
r + 56.2 = -77.700001023

Simplifying
r + 56.2 = -77.700001023

Reorder the terms:
56.2 + r = -77.700001023

Solving
56.2 + r = -77.700001023

Solving for variable 'r'.

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

Add '-56.2' to each side of the equation.
56.2 + -56.2 + r = -77.700001023 + -56.2

Combine like terms: 56.2 + -56.2 = 0.0
0.0 + r = -77.700001023 + -56.2
r = -77.700001023 + -56.2

Combine like terms: -77.700001023 + -56.2 = -133.900001023
r = -133.900001023

Simplifying
r = -133.900001023

Solution
The solution to the problem is based on the solutions
from the subproblems.
r = {21.500001023, -133.900001023}