//Computes the area of a circle and the volume of a sphere.
//Uses the same radius for both calculations.
#include <iostream.h>
#include <math.h>

const double PI = 3.14159;

double area(double radius);
//Returns the area of a circle with the specified radius.

double volume(double radius);
//Returns the volume of a sphere with the specified radius.

void get_input(double& radius);

void show_results(double radius, double area, double volume);


int main( )
{
    double radius_of_both, area_of_circle, volume_of_sphere;

    get_input(radius_of_both);
    area_of_circle = area(radius_of_both);
    volume_of_sphere = volume(radius_of_both);
    show_results(radius_of_both, 
                          area_of_circle, volume_of_sphere);
    return 0;
}


double area(double radius)
{
    return (PI * pow(radius, 2));
}

double volume(double radius)
{
    return ((4.0/3.0) * PI * pow(radius, 3));
}


//Uses iostream.h:
void get_input(double& radius)
{
    cout << "Enter a radius to use for both a circle\n"
         << "and a sphere (in inches): ";
    cin >> radius;
}


//Uses iostream.h:
void show_results(double radius, double area, double volume)
{
    cout << "Radius = " << radius << " inches\n"
         << "Area of circle = " << area 
         << " square inches\n"
         << "Volume of sphere = " << volume
         << " cubic inches\n";
}