Program to calculate area of inner circle which passes through center of outer circle and touches its circumference

Given a circle C1 and it’s a radius r1. And one another circle C2 whose passes through center of circle C1 and touch the circumference of circle C1. The task is to find out the area of circle C2.
Examples:

Input: r1 = 4
Output:Area of circle c2 = 12.56

Input: r1 = 7
Output:Area of circle c2 = 38.465

Approuch:
Radius r2 of circle C2 is  \ r2 = r1/2 \ .
So we know that the area of circle is \  Area = \pi r^2 \ .

Below is the implementation of the above approach:

C++

filter_none

edit
close

play_arrow

link
brightness_4
code

// C++ implementation of the above approach
#include<bits/stdc++.h> 
#include <iostream>
using namespace std;
  
// Function calculate the area of the inner circle
double innerCirclearea(double radius)
{
  
    // the radius cannot be negative
    if (radius < 0) 
    {
        return -1;
    }
  
    // area of the circle
    double r = radius / 2;
    double Area = (3.14 * pow(r, 2));
  
    return Area;
}
  
// Driver Code
int main()
{
      
    double radius = 4;
    cout << ("Area of circle c2 = ",
                innerCirclearea(radius));
    return 0;
}
  
// This code is contributed by jit_t.

chevron_right


Java

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java implementation of the above approach
  
class GFG {
  
    // Function calculate the area of the inner circle
    static double innerCirclearea(double radius)
    {
  
        // the radius cannot be negative
        if (radius < 0) {
            return -1;
        }
  
        // area of the circle
        double r = radius / 2;
        double Area = (3.14 * Math.pow(r, 2));
  
        return Area;
    }
  
    // Driver Code
    public static void main(String arr[])
    {
        double radius = 4;
        System.out.println("Area of circle c2 = "
                           + innerCirclearea(radius));
    }
}

chevron_right


Python3

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python3 implementation of the above approach 
  
# Function calculate the area of the inner circle 
def innerCirclearea(radius) :
  
    # the radius cannot be negative 
    if (radius < 0) :
        return -1;
          
    # area of the circle
    r = radius / 2;
    Area = (3.14 * pow(r, 2)); 
  
    return Area; 
      
# Driver Code 
if __name__ == "__main__" :
      
    radius = 4
    print("Area of circle c2 ="
           innerCirclearea(radius)); 
  
# This code is contributed by AnkitRai01

chevron_right


C#

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# Implementation of the above approach
using System;
      
class GFG 
{
  
    // Function calculate the area 
    // of the inner circle
    static double innerCirclearea(double radius)
    {
  
        // the radius cannot be negative
        if (radius < 0) 
        {
            return -1;
        }
  
        // area of the circle
        double r = radius / 2;
        double Area = (3.14 * Math.Pow(r, 2));
  
        return Area;
    }
  
    // Driver Code
    public static void Main(String []arr)
    {
        double radius = 4;
        Console.WriteLine("Area of circle c2 = "
                          innerCirclearea(radius));
    }
  
// This code is contributed by PrinciRaj1992

chevron_right


Output:

Area of circle c2 = 12.56


My Personal Notes arrow_drop_up

Just another competitive programmer and hard worker

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.





Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.