# Is there a way that I can get there to be only one input in my program?

I am writing a program where I calculate the area of a circle, the volume of a sphere, and the surface area of a sphere and I need a way to get one source of user input. I don’t want the program to keep asking for user input the way that it is in the functions.

I want my program to run like this:

`Enter a radius in inches: 3.3`
`Area of a circle is 34.21 square inches`
`Volume of a sphere is 150.53 cubic inches`
`Surface area of a sphere is 136.85 square inches`

This is what I have so far though:

``````#include <iostream>
#include <cmath>
#define Pi 3.1415
using namespace std;

void area_of_circle() {
std::cout << "Enter a radius in inches: " << endl;
double areaCircle = Pi * radius * radius;
std::cout << "The area of the circle is " << std::ceil(areaCircle * 100.0) / 100.0 << " square inches";
}

void volume_of_sphere() {
std::cout << "Enter a radius in inches: " << endl;
double volumeSphere = (4/3) * Pi * radius * radius * radius;
std::cout << "The volume of the sphere is " << std::ceil(volumeSphere * 100.0) / 100.0 << " cubic inches";
}

void surface_area_of_sphere() {
std::cout << "Enter a radius in inches: " << endl;
double surfaceAreaSphere = 4 * Pi * radius * radius;
std::cout << "The volume of the sphere is " << std::ceil(surfaceAreaSphere * 100.0) / 100.0 << " square inches";

}

int main() {
area_of_circle();
volume_of_sphere();
surface_area_of_sphere();
}
``````

Can someone help, please?

Do you mean this?

``````void input() {
std::cout << "Enter a radius in inches: " << endl;
}

int main() {
area_of_circle();
volume_of_sphere();
surface_area_of_sphere();
}
``````

I tried putting `double radius = input();` into my functions and then typing

`````` double radius = input();
``````

and it’s not working.

Declare a parameter as in:

``````void area_of_circle(radius) {
double radius = input();
std::cout << "Enter a radius in inches: " << endl;
double areaCircle = Pi * radius * radius;
std::cout << "The area of the circle is " << std::ceil(areaCircle * 100.0) / 100.0 << " square inches";
}

int main() {
double radius = input();
}
``````

Is this what you meant?

``````#include <iostream>
#include <cmath>
#define Pi 3.1415
using namespace std;

double input() {
std::cout << "Enter a radius in inches: " << endl;
}

void area_of_circle(double radius) {
double areaCircle = Pi * radius * radius;
std::cout << "The area of the circle is " << std::ceil(areaCircle * 100.0) / 100.0 << " square inches\n";
}

void volume_of_sphere(double radius) {
double volumeSphere = (4.0/3.0) * Pi * radius * radius * radius;
std::cout << "The volume of the sphere is " << std::ceil(volumeSphere * 100.0) / 100.0 << " cubic inches\n";
}

void surface_area_of_sphere(double radius) {
double surfaceAreaSphere = 4 * Pi * radius * radius;
std::cout << "The volume of the sphere is " << std::ceil(surfaceAreaSphere * 100.0) / 100.0 << " square inches";
}

int main() {
double radius = input();