C++ Code Example: volume and surface of a cube

This program calculates the volume and the surface area of a cube in separate functions.

#include <iostream>
using namespace std;

double Volume (double a) {
	double volume;
	volume = a * a * a;
	return volume;
}

double Surface (double a) {
	double surface;
	surface = 6 * a * a;
	return surface;
}

int main () {
	double edgeLength;
	cout << "Please enter the edge length: " << endl;
	cin >> edgeLength;

	cout << "Volume: " << Volume(edgeLength) << endl;
	cout << "Surface: " << Surface(edgeLength) << endl;
	return 0;
}
Output
Please enter the edge length: 
5
Volume: 125
Surface: 150