 Open in App
Not now

# Program to calculate area and perimeter of equilateral triangle

• Difficulty Level : Expert
• Last Updated : 31 Jul, 2022

An equilateral triangle is a triangle in which all three sides and angles are equal. All three internal angles of equilateral triangle measures 60 degree.

• If we know the length of each sides of equilateral triangle, then we can use below mentioned formula to calculate area of equilateral triangle.
`Area of Equilateral Triangle = (sqrt(3)/4) * a * a    `
• If we know the length of altitude of equilateral triangle along with the length of side, then we can use below mentioned formula to calculate it’s area.
`Area of Equilateral Triangle = (1/2) x Side x Altitude`

Perimeter of Equilateral Triangle :

`Perimeter of Equilateral Triangle :  3 X a`

How does the area formula work?
Let us take a look at below diagram. We know are of a triangle is 1/2 * base * height. The value of h is sqrt(a2 – (a/2)2) = sqrt(3) * a / 2. So the area becomes 1/2 * a * (sqrt(3) * a / 2) = (sqrt(3)/4) * a * a Examples:

```Input : side = 4
Output : Area of Equilateral Triangle: 6.9282
Perimeter of Equilateral Triangle: 12
Input : side = 12
Output : Area of Equilateral Triangle: 62.3538
Perimeter of Equilateral Triangle: 36```

## C++

 `// CPP program to find area` `// and perimeter of equilateral triangle` `#include ` `using` `namespace` `std;`   `// Function to calculate Area` `// of equilateral triangle` `float` `area_equi_triangle(``float` `side)` `{` `    ``return` `sqrt``(3) / 4 * side * side;` `}`   `// Function to calculate Perimeter` `// of equilateral triangle` `float` `peri_equi_triangle(``float` `side)` `{` `    ``return` `3 * side;` `}`   `// Driver Code` `int` `main()` `{` `    ``float` `side = 4;` `    ``cout << ``"Area of Equilateral Triangle: "` `        ``<< area_equi_triangle(side) << endl;` `    ``cout << ``"Perimeter of Equilateral Triangle: "` `        ``<< peri_equi_triangle(side);` `    ``return` `0;` `}`

## Java

 `// Java Program to find area and` `// perimeter of equilateral triangle` `import` `java.io.*;`   `class` `GFG` `{` `    ``// Function to calculate` `    ``// Area of equilateral triangle` `    ``static` `float` `area_equi_triangle(``float` `side)` `    ``{`   `        ``return` `(``float``)(((Math.sqrt(``3``)) / ``4``) *` `                        ``side * side);` `    ``}`   `    ``// Function to calculate` `    ``// Perimeter of equilateral` `    ``// triangle` `    ``static` `float` `peri_equi_triangle(``float` `side)` `    ``{` `        ``return` `3` `* side;` `    ``}` `    `  `    ``// Driver Code` `    ``public` `static` `void` `main(String arg[])` `    ``{` `        ``float` `side = ``4``;` `        ``System.out.print(``"Area of Equilateral Triangle:"``);` `        ``System.out.println(area_equi_triangle(side));` `        ``System.out.print(``"Perimeter of Equilateral Triangle:"``);` `        ``System.out.println(peri_equi_triangle(side));` `    ``}` `}`   `// This code is contributed` `// by Anant Agarwal.`

## Python

 `# Python3 program to calculate Area and` `# Perimeter of equilateral Triangle`   `# Importing Math library for sqrt` `from` `math ``import` `*`   `# Function to calculate Area` `# of equilateral triangle` `def` `area_equilateral( side ):` `    ``area ``=` `(sqrt(``3``) ``/` `4``) ``*` `side ``*` `side` `    ``print` `(``"Area of Equilateral Triangle: % f"``%` `area)`   `# Function to calculate Perimeter` `# of equilateral triangle` `def` `perimeter( side ):` `    ``perimeter ``=` `3` `*` `side` `    ``print` `(``"Perimeter of Equilateral Triangle: % f"``%` `perimeter)` `    `  `# Driver code` `side ``=` `4` `area_equilateral( side )` `perimeter( side )`

## C#

 `// C# Program to find area and` `// perimeter of equilateral triangle` `using` `System;`   `class` `GFG` `{` `    ``// Function to calculate` `    ``// Area of equilateral triangle` `    ``static` `float` `area_equi_triangle(``float` `side)` `    ``{`   `        ``return` `(``float``)(((Math.Sqrt(3)) / 4) *` `                        ``side * side);` `    ``}`   `    ``// Function to calculate` `    ``// Perimeter of equilateral` `    ``// triangle` `    ``static` `float` `peri_equi_triangle(``float` `side)` `    ``{` `        ``return` `3 * side;` `    ``}` `    `  `    ``// Driver Code` `    ``public` `static` `void` `Main()` `    ``{` `        ``float` `side = 4;` `        ``Console.Write(``"Area of Equilateral Triangle:"``);` `        ``Console.WriteLine(area_equi_triangle(side));` `        ``Console.Write(``"Perimeter of Equilateral Triangle:"``);` `        ``Console.WriteLine(peri_equi_triangle(side));` `    ``}` `}`   `// This code is contributed` `// by vt_m.`

## PHP

 ``

## Javascript

 ``

Output

```Area of Equilateral Triangle: 6.9282
Perimeter of Equilateral Triangle: 12```

Time Complexity: O(1)

Auxiliary Space: O(1)

My Personal Notes arrow_drop_up
Related Articles