Method Name Expected

`double areaRaw = perimeter(pSubSidA * pSubSidB * pSubSidC);`

There is only one And

`perimeter`

is a `double`

variable:double perimeter = (sideA + sideB + sideC) / 2;not a method, so it looks at your code, sees this:

`double variable = aName(parameter list);`

and expects aName to be a method. so, it complains: you can't "call" a variable, that doesn't make any sense!I think you need to go back to basic maths: Area of a triangle given three sides - Heron's Formula - Math Open Reference[^]

So, calculate p: (a + b + c)/2

Then area = Sqrt(p * (p - a) * (p - b) * (p -c))

You've calculated p, that's fine - but you need the multiply sign:

C#

`double areaRaw = perimeter * (pSubSidA * pSubSidB * pSubSidC);`