Start here:

#include <iostream>

using namespace std;

const double PI = atan(1.0) * 4;
double area;

return area;
}

int main() {

cout << "I would like to compute the area of a circle for you.\n\n";

cout << "The area is " << circle_area(radius) << endl << endl;

system("pause");
return 0;
}

End here:

#include <iostream>

using namespace std;

const double PI = atan(1.0) * 4;
double area;

return area;
}

double cylinder_volume(double radius, double height) {
double volume;

return volume;
}

int main() {

cout << "I would like to compute the volume of a cylinder for you.\n\n";
cout << "Please give the height of the desired cylinder: ";
cin >> height;

cout << "The volume is " << cylinder_volume(radius, height) << endl << endl;

system("pause");
return 0;
}