Write a program that calculates area/volume of various shapes.

1st call function w/ prototype: void showMenu(int &); which displays menu

this is what the output should be:

this is what i have so far... yeah, fairly lost

// This program is designed to allow the user to calculate the area and volume of various shapes.

#include <iostream>

#include <iomanip>

using namespace std;

void showMenu (int &);

double area (double length, double width);

double area (double radius);

double volume (double length, double width, double height);

double volume (double radius);

int main()

{

int selection;

double length;

double width;

double height;

double radius;

cout << fixed << showpoint << setprecision(2);

cout << "1. Calculate the area of a rectangle" << endl;

cout << "2. Calculate the area of a circle" << endl;

cout << "3. Calculate the volume of a box" << endl;

cout << "4. Calculate the volume of a sphere" << endl;

cout << "5. Quit" << endl;

cin >> "Please select 1-5: " >> selection;

cout << endl;