undefined reference error for void function

[blazinaway]

Hello all...i am really new to C++ programming and i cant figure out why this error keeps popping up...if someone can help, i would really appreciate it

here is my code....compiler says error occurs on line 34:"undefinded reference to findCircleArea (double)...."

#include <iostream>
using namespace std;

void displayMenu();
int getChoice();
void findSquareArea(double);
void findCircleArea(double);
void findTriangleArea(double, double);

int main()
{
const double pi = 3.14159;
double side, radius, length, width;
int choice;

do
{
displayMenu();
choice = getChoice();
if (choice != 4)
{
switch (choice)
{
case 1: cout << "Enter side length: ";
cin >> side;
findSquareArea(side);
break;
case 2: cout << "Enter radius: ";
cin >> radius;
findCircleArea(radius);
break;
case 3: cout << "Enter length and width";
cin >> length >> width;
findTriangleArea(length, width);
}
}
} while (choice != 4);
return 0;
}

void displayMenu()
{
cout << "\nArea Finding Program - Please Select Shape\n\n";
cout << "1 -- square\n";
cout << "2 -- circle\n";
cout << "3 -- right triangle\n";
cout << "4 -- quit";
}

int getChoice()
{
int choice;

cin >> choice;
while (choice < 1 || choice > 4)
{
cout << "The only valid choices are 1-4. Please re-enter. ";
cin >> choice;
}
return choice;
}

void findSquareArea(double side)
{
cout << endl;
cout << "The area of the square is " << side * side;
}

void findCircleArea(double radius, const double pi = 3.14159)
{
cout << endl;
cout << "The area of the circle is " << radius * radius * pi;
}

void findTriangleArea(double length, double width)
{
cout << endl;
cout << "The area of the triangle is " << (length *width)/ 2;

}

[guestgulkan]

Because you haven't written a function findCircleArea (double)