You want an easy way to find the Area, Surface Area, Perimeter or Volume? Or you are looking for an easy way to find different equations like: Slope Of Line, Quadratic Equation, Standard Equation Of Circle, Quadratic Formula, Point Slope Equation or even Slope Intercept Equation? Then check out MathHelper.io nuget package to help you with your math problems.
There is some redundant logic which is already solved in .Net.
IMHO the 'public static int Sum(this List numbers)' method is redundant and can be removed.
Fixed some formatting as well.