"missing function header" error

Hey,

I am just getting started building programs with multiple modulus/functions. I am having trouble getting the syntax correct. I keeping on getting this error when trying to fun this program. This is a program to calculate the area of a triangle using Heron's Formula.

1>c:\users\brendan\desktop\lab5no2\lab5no2\lab5no2.cpp(26): error C2447: '{' : missing function header (old-style formal list?)

Any pointers are greatly appreciated.

Thanks,

Bob Sancamento

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;

double areaOfaTriangle(double, double, double);

int main()
{

	double varA, varB, varC;

	cout << "What is the Length of SIDE A? :";
	cin >> varA;
	cout << "\nWhat is the Length of SIDE B? :";
	cin >> varB;
	cout << "\nWhat is the Length of SIDE C? :";
	cin >> varC;

	cout << "The are of the triang is " << areaOfaTriangle( varA, varB, varC) << endl;

	return 0;
}

double areaOfaTriangle(double varA1, double varB1, double varC1);
{

	double varS, varX, aRea;

	varS = (varA1 + varB1 + varC1 +)/2;

	varX = varS * ((varS - varA1)*(varS-varB1)*(varS-varC1));

	if (varX <= 0)
	{
		aRea = sqrt[varX];

	}
	else
	{
		aRea=-1;
	}
	

return aRea;

}

Sorry i did this wrong lets try again