Hello, I'm just learning C++ and I'm getting an error with a program that is driving me nuts, and I'm not exactly sure how to resolve it. Can anyone help me?

AreaCalculator.obj : error LNK2019: unresolved external symbol "double __cdecl AreaOfTriangle(double,double)" (?AreaOfTriangle@@YANNN@Z) referenced in function _main
\\.psf\Home\Documents\Visual Studio 2008\Projects\AreaCalculator\Debug\AreaCalculator.exe : fatal error LNK1120: 1 unresolved externals

``````#include <iostream>		//for using cin and cout
#include <conio.h>		//for using getch()
#include <cmath>		//for using pow

using namespace std;

double AreaOfRectangle(/* in */ double length,   //length of rectangle
/* in */ double width);   //width of rectangle
//Purpose: Calculate the area of a rectangle
//Precondition:
//         length and width are assigned the length and width of the rectangle.
//		   length > 0 and width > 0
//Postcondition:
//         Returns the area of the rectangle

//Purpose: Calculate the area of a circle
//Precondition:
//Postcondition:
//         Returns the area of the circle.

double AreaOfTriangle (/* in */ double base, //length of triangle base
/* in */ double height); //height of triangle
//Purpose:	Calculate the area of a triangle
//Precondition:
//			base and height are assigned the base and height of the triangle
//			base > 0 and height > 0
//Postcondition:
//			Returns the area of the triangle.

int main()
{
double length;		//length of rectangle
double width;		//width of rectangle
double base;		//base length of triangle
double height;		//height of triangle
int number;		//number entered to indicate user's selection

cout << "*** Calculation of area ***\n\n\n";

cout << "Enter 1 to calculate the area of a rectangle, \n";
cout << "      2 to calculate the area of a circle, or\n";
cout << "      3 to calculate the area of a triangle.\n\n";
cout << "Please enter 1, 2, or 3: ";
cin >> number;
cout << endl;

//calculate area of rectangle or area of circle
if (number == 1)	//for calculating the area of rectangle
{
//prompt for and read the length and width of rectangle
cout << "Enter the length of the rectangle in inches: ";
cin >> length;
cout << "Enter the width of the rectangle in inches: ";
cin >> width;

//Call function to calculate area of rectangle, and display the area
cout << endl << "Area of rectangle is: " << AreaOfRectangle(length,width)
<< " square inches.\n\n";
}
else if (number == 2 )	//for calculating the area of circle
{
cout << "Enter the radius of the circle in inches: ";

//Call function to calculate area of circle, and display the area
cout << endl << "Area of circle is " << AreaOfCircle(radius) << " square inches.\n\n";
}
else if (number == 3)	//for calculating the area of a triangle
{
//prompt for and read the base and height of the triangle
cout << "Enter the base of the triangle in inches: ";
cin >> base;
cout << "Enter the height of the triandgle in inches: ";
cin >> height;

//Call the function to calculate the area of a triangle, and display the area
cout << endl << "Area of triangle is " << AreaOfTriangle(base,height) << "square inches.\n\n";
}
else
cout << "Invalid number entered. \n\n"; //number other than 1 and 2 entered

_getch();	//to hold the screen for viewing
return 0;
}

//-----------------------------------------------------------------------------------
double AreaOfRectangle(/* in */ double length,  //length of rectangle
/* in */ double width )   //width of rectangle
{
double areaRect;	//area of rectangle

//calculate the area
areaRect = length * width;

return areaRect;
}

//-------------------------------------------------------------------------------------

{
const double PI = 3.14159;
double areaCirc;   //area of circle

//calculate area of circle
areaCirc =  PI * pow(radius,2.0);  //note the use of the predefined function pow

return areaCirc;
}

//--------------------------------------------------------------------------------------
double AreaOfTrianglw(/* in */ double base, //length of base of triangle
/* in */ double height) //height of triangle
{

double areaTri;	//area of triangle

//calculate area of triangle
areaTri = (base * height) / 2;

return areaTri;
}``````

Thanks!

Okay nevermind....just a typo, my bad.

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