Program to find diameter / area / circumfrance - of a circle in C++

ArcMath.cpp

#include <iostream>

#include <string>

#include <iomanip>

#include <fstream>

#include <cmath>

using namespace std;

double distance(int x1, int y1, int x2, int y2) {
  double r;
  double distance;
  r = sqrt(pow((x2 - x1), 2) + pow((y2 - y1), 2));
  distance = r * 2;
  return distance;
}

double radius(int x1, int y1, int x2, int y2) {
  double r;
  r = sqrt(pow((x2 - x1), 2) + pow((y2 - y1), 2));
  return r;
}

double circumference(double cRadius) {
  double circumference;
  circumference = 2 * 3.1416 * cRadius; //2(PI)r
  return circumference;
}

double area(double cRadius) {
  double area;
  area = 3.1416 * pow(cRadius, 2); //(PI)r^2
  return area;
}

int main() {
  int x1, y1; //first point
  int x2, y2; //second point

  double cRadius;
  double cDiam;
  double cCircumf;
  double cArea;

  double tst = 2.00;

  //prompt for center and point
  cout << "Center X: ";
  cin >> x1;
  cout << "Center Y: ";
  cin >> y1;

  cout << "Point X: ";
  cin >> x2;
  cout << "Point Y: ";
  cin >> y2;

  //find radius
  cRadius = radius(x1, y1, x2, y2);
  //cout << fixed << showpoint;
  cout << setprecision(2) << fixed;
  cout << "Radius = " << cRadius << endl;

  //find diameter (same as distance)
  cDiam = distance(x1, y1, x2, y2);
  cout << "Distance = " << cDiam << endl;

  //find circumf
  cCircumf = circumference(cRadius);
  cout << "Circumference = " << cCircumf << endl;

  //find area
  cArea = area(cRadius);
  cout << "Area = " << cArea << endl;

  return 0;
}