# Program to find the Area and Perimeter of a Semicircle

Last Updated : 21 Aug, 2022

Given the radius of the semicircle as r, the task is to find out the Area and Perimeter of that semicircle.
Examples:

```Input: r = 10
Output: Area = 157.00, Perimeter = 31.4

Input: r = 25
Output: Area =981.250000, Perimeter = 78.500000```

Approach:
In mathematics, a semicircle is a one-dimensional locus of points that forms half of a circle. The area of a semicircle is half the area of the circle from which it is made. Any diameter of a circle cuts it into two equal semicircles.

Area of Semi-Circle = 1?2 * ? *r2
Perimeter of Semi-Circle = ? *r
where “r” is the radius of the semicircle.

Below is the implementation of the above approach:

## C++

 `// C++ program to find the` `// Area and Perimeter of a Semicircle`   `#include ` `using` `namespace` `std;`   `// Function for calculating the area` `float` `area(``float` `r)` `{` `    ``// Formula for finding the area` `    ``return` `(0.5)*(3.14)*(r * r);` `}`   `// Function for calculating the perimeter` `float` `perimeter(``float` `r)` `{` `    ``// Formula for finding the perimeter` `    ``return` `(3.14)*(r);` `}`   `// driver code` `int` `main()` `{`   `    ``// Get the radius` `    ``int` `r = 10;`   `    ``// Find the area ` `    ``cout << ``"The Area of Semicircle: "` `         ``<< area(r) << endl;`   `    ``// Find the perimeter` `    ``cout << ``"The Perimeter of Semicircle: "` `         ``<< perimeter(r) << endl;`   `    ``return` `0;` `}`

## C

 `// C program to find the` `// Area and Perimeter of a Semicircle`   `#include `   `// Function for calculating the area` `float` `area(``float` `r)` `{` `    ``// Formula for finding the area` `    ``return` `(0.5)*(3.14)*(r * r);` `}`   `// Function for calculating the perimeter` `float` `perimeter(``float` `r)` `{` `    ``// Formula for finding the perimeter` `    ``return` `(3.14)*(r);` `}`   `// driver code` `int` `main()` `{`   `    ``// Get the radius` `    ``float` `r = 10;`   `    ``// Find the area` `    ``printf``(``"The Area of Semicircle: %f\n"``,` `        ``area(r));`   `    ``// Find the perimeter` `    ``printf``(``"The Perimeter of Semicircle: %f\n"``,` `        ``perimeter(r));` `    ``return` `0;` `}`

## Java

 `// Java program to find the` `// Area and Perimeter of a Semicircle`   `import` `java.io.*;`   `class` `GFG {`   `// Function for calculating the area` `static` `float` `area(``float` `r)` `{` `    ``// Formula for finding the area` `    ``return` `(``float``)((``0.5``)*(``3.14``)*(r * r));` `}`   `// Function for calculating the perimeter` `static` `float` `perimeter(``float` `r)` `{` `    ``// Formula for finding the perimeter` `    ``return` `(``float``)((``3.14``)*(r));` `}`   `// driver code`   `    ``public` `static` `void` `main (String[] args) {` `    ``// Get the radius` `    ``float` `r = ``10``;`   `    ``// Find the area` `    ``System.out.println(``"The Area of Semicircle: "``+` `        ``area(r));`   `    ``// Find the perimeter` `    ``System.out.println(``"The Perimeter of Semicircle:"``+` `        ``+perimeter(r));` `    ``}` `}` ` ``// This code is contributed` `// by anuj_67..`

## Python3

 `# Python3 program to find the` `# Area and Perimeter of a Semicircle`   `# Function for calculating the area` `def` `area(r):` `    `  `    ``# Formula for finding the area` `    ``return` `(``0.5``)``*``(``3.14``)``*``(r ``*` `r)`   `#Function for calculating the perimeter` `def` `perimeter(r):` `    `  `    ``#Formula for finding the perimeter` `    ``return` `(``3.14``)``*``(r)`   `# driver code` `if` `__name__``=``=``'__main__'``:` `    ``# Get the radius` `    ``r ``=` `10`   `    ``# Find the area ` `    ``print` `(``"The Area of Semicircle: "` `           ``,area(r))`   `    ``# Find the perimeter` `    ``print` `(``"The Perimeter of Semicircle: "` `           ``,perimeter(r))` `           `  `# This code is contributed by ` `# SURENDRA_GANGWAR`

## C#

 `// C# program to find the` `// Area and Perimeter of a Semicircle` `using` `System;`   `class` `GFG {`   `// Function for calculating the area` `static` `float` `area(``float` `r)` `{` `    ``// Formula for finding the area` `    ``return` `(``float``)((0.5)*(3.14)*(r * r));` `}`   `// Function for calculating the perimeter` `static` `float` `perimeter(``float` `r)` `{` `    ``// Formula for finding the perimeter` `    ``return` `(``float``)((3.14)*(r));` `}`   `// Driver Code` `public` `static` `void` `Main()` `{` `    ``// Get the radius` `    ``float` `r = 10;` `    `  `    ``// Find the area` `    ``Console.WriteLine(``"The Area of Semicircle: "` `+` `                                         ``area(r));` `    `  `    ``// Find the perimeter` `    ``Console.WriteLine(``"The Perimeter of Semicircle:"` `+ ` `                                        ``perimeter(r));` `}` `}`   `// This code is contributed` `// by Akanksha Rai(Abby_akku)`

## PHP

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## Javascript

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Output:

```The Area of Semicircle: 157.000000
The Perimeter of Semicircle: 31.400000```

Time Complexity: O(1), since there is no loop or recursion.

Auxiliary Space: O(1), since no extra space has been taken.