# Calculate the Area of the Circle

Problem Statement: Given the radius of the circle, calculate the area of the circle.

Examples:

```Example 1:
Input: N = 5
Output: 78.5
Explanation: Using formula  πr2 for finding area of circle we get area as 78.5

Example 2:
Input: N = 4
Output: 50.2
Explanation: Using formula  πr2 for finding area of circle we get area as 50.2

```

### Solution

Disclaimer: Don’t jump directly to the solution, try it out yourself first.

Approach:

• We know that the area of the circle is  πr2.
• So taking a variable double to store decimal digits as our ans.
• And multiplying pi with the square of the radius gives us the area of the circle.

Code:

## C++ Code

``````#include <bits/stdc++.h>

using namespace std;

class Area {

public:

void areaOfCircle(int n) {

double ans = 3.14 * n * n; // Area of circle = πr2
cout << "Area of circle is : ";
cout << ans;
}
};
int main() {

int n = 5;

Area p1;
p1.areaOfCircle(n);

return 0;
}
``````

Output:

Area of circle is: 78.5

Time Complexity: O(1)

Space Complexity:  O(1)

## Java Code

``````class Solution {

public static void areaOfCircle(int n) {

double ans = 3.14 * n * n; // Area of circle = πr2
System.out.print("Area of circle is : " + ans);

}
public static void main(String args[]) {
int n = 5;
areaOfCircle(n);
}
}
``````

Output:

Area of circle is: 78.5

Time Complexity: O(1)

Space Complexity:  O(1)