#include <iostream>

using namespace std;

const float PI = 3.141592653558979323846;

/*

Area of Circle is given by: PI * (r*r)

Circumference of circle is given by: PI * (2r)

*/

int main() {

// declare and initialize all necessary variables

// initialized vars to 0, so I would know what their starting value was.

float area = 0;

float radius = 0;

float circumference = 0;

// ask for input of radius

cout << "Please enter the radius: ";

// store the input into a variable

cin >> radius;

// calculate the area and store the result in a variable

area = PI * (radius * radius);

// output the area

cout << "The area is " << area << endl;

// calculate the circumference

circumference = 2 * PI * radius;

// output the circumference

cout << "The circumference is " << circumference << endl;

}