# Calculate area of equilateral triangle

The problem involves calculating the area of an equilateral triangle given the length of its side. An equilateral triangle is a type of triangle in which all three sides are of equal length and all three angles are 60 degrees. Calculating the area of an equilateral triangle is a basic geometric calculation used in various fields such as mathematics, engineering, and design.

## Problem Statement

Given the length of a side of an equilateral triangle, we need to calculate and output the area of the triangle. The side length is provided as input, and we are required to use the formula for the area of an equilateral triangle to find the area.

## Example

Consider an equilateral triangle with a side length of 5. This equilateral triangle can be visualized as follows:

``````
/\
/  \
/____\
5.0

``````

## Idea to Solve

To solve this problem, we can follow these steps:

1. Calculate the area of the equilateral triangle using the formula: area = (sqrt(3) / 4) * (side * side).
2. Use the provided value for the side length to compute the area.

## Pseudocode

``````function equilateral_triangle_area(side):
area = (sqrt(3) / 4) * (side * side)
return area

for each test case:
side = equilateral triangle side length
result = equilateral_triangle_area(side)
print("Equilateral triangle [ side :", side, "]")
print("Area :", result)``````

## Algorithm Explanation

1. For each test case, calculate the area of the equilateral triangle using the provided formula.
2. Print the triangle's side length and the calculated area.

## Code Solution

``````//C Program
//Calculate area of equilateral triangle
#include <stdio.h>
#include <math.h>

///Calculate area of equilateral triangle by given side
void equilateral_triangle(double side)
{
//Calculate area of equilateral triangle
double area = (sqrt(3) / 4) * (side * side);
//Display the result of right angle triangle area
printf(" Equilateral triangle  [ side : %lf ] ", side);
printf("\n Area : %lf\n\n", area);
}
int main()
{
//Test Cases
equilateral_triangle(5);
equilateral_triangle(10);
equilateral_triangle(7.5);
return 0;
}``````

#### Output

`````` Equilateral triangle  [ side : 5.000000 ]
Area : 10.825318

Equilateral triangle  [ side : 10.000000 ]
Area : 43.301270

Equilateral triangle  [ side : 7.500000 ]
Area : 24.356964
``````
``````// Java Program
// Calculate area of equilateral triangle
class EquilateralTriangle
{
//Calculate area of equilateral triangle by given side
public void equilateral_triangle(double side)
{
//Calculate area of equilateral triangle
double area = (Math.sqrt(3) / 4) * (side * side);
//Display the result of right angle triangle area
System.out.print(" Equilateral triangle [ side : " + side + " ] ");
System.out.print("\n Area : " + area + "\n\n");
}
public static void main(String[] args)
{
EquilateralTriangle obj = new EquilateralTriangle();
//Test Cases
obj.equilateral_triangle(5);
obj.equilateral_triangle(10);
obj.equilateral_triangle(7.5);
}
}``````

#### Output

`````` Equilateral triangle [ side : 5.0 ]
Area : 10.825317547305483

Equilateral triangle [ side : 10.0 ]
Area : 43.30127018922193

Equilateral triangle [ side : 7.5 ]
Area : 24.356964481437334
``````
``````// C++ Program
// Calculate area of equilateral triangle
#include<iostream>
#include <math.h>
using namespace std;
class EquilateralTriangle
{
public:
//Calculate area of equilateral triangle by given side
void equilateral_triangle(double side)
{
//Calculate area of equilateral triangle
double area = (sqrt(3) / 4) *(side *side);
cout << " Equilateral triangle [ side : " << side << " ] ";
cout << "\n Area : " << area << "\n\n";
}
};
int main()
{
EquilateralTriangle obj =  EquilateralTriangle();
//Test Cases
obj.equilateral_triangle(5);
obj.equilateral_triangle(10);
obj.equilateral_triangle(7.5);
return 0;
}``````

#### Output

`````` Equilateral triangle [ side : 5 ]
Area : 10.8253

Equilateral triangle [ side : 10 ]
Area : 43.3013

Equilateral triangle [ side : 7.5 ]
Area : 24.357
``````
``````// C# Program
// Calculate area of equilateral triangle
using System;
class EquilateralTriangle
{
//Calculate area of equilateral triangle by given side
public void equilateral_triangle(double side)
{
//Calculate area of equilateral triangle
double area = (Math.Sqrt(3) / 4) * (side * side);
Console.Write(" Equilateral triangle [ side : " + side + " ] ");
Console.Write("\n Area : " + area + "\n\n");
}
public static void Main(String[] args)
{
EquilateralTriangle obj = new EquilateralTriangle();
//Test Cases
obj.equilateral_triangle(5);
obj.equilateral_triangle(10);
obj.equilateral_triangle(7.5);
}
}``````

#### Output

`````` Equilateral triangle [ side : 5 ]
Area : 10.8253175473055

Equilateral triangle [ side : 10 ]
Area : 43.3012701892219

Equilateral triangle [ side : 7.5 ]
Area : 24.3569644814373
``````
``````<?php
// Php Program
// Calculate area of equilateral triangle
class EquilateralTriangle
{
//Calculate area of equilateral triangle by given side
public 	function equilateral_triangle(\$side)
{
//Calculate area of equilateral triangle
\$area = (sqrt(3) / 4) *(\$side *\$side);
//Display the result of right angle triangle area
echo(" Equilateral triangle [ side : ". \$side ." ] ");
echo("\n Area : ". \$area ."\n\n");
}
}

function main()
{
\$obj = new EquilateralTriangle();
//Test Cases
\$obj->equilateral_triangle(5);
\$obj->equilateral_triangle(10);
\$obj->equilateral_triangle(7.5);
}
main();``````

#### Output

`````` Equilateral triangle [ side : 5 ]
Area : 10.825317547305

Equilateral triangle [ side : 10 ]
Area : 43.301270189222

Equilateral triangle [ side : 7.5 ]
Area : 24.356964481437
``````
``````// Node Js Program
// Calculate area of equilateral triangle
class EquilateralTriangle
{
//Calculate area of equilateral triangle by given side
equilateral_triangle(side)
{
//Calculate area of equilateral triangle
var area = (Math.sqrt(3) / 4) *(side *side);
//Display the result of right angle triangle area
process.stdout.write(" Equilateral triangle [ side : " + side + " ] ");
process.stdout.write("\n Area : " + area + "\n\n");
}
}

function main(args)
{
var obj = new EquilateralTriangle();
//Test Cases
obj.equilateral_triangle(5);
obj.equilateral_triangle(10);
obj.equilateral_triangle(7.5);
}
main();``````

#### Output

`````` Equilateral triangle [ side : 5 ]
Area : 10.825317547305483

Equilateral triangle [ side : 10 ]
Area : 43.30127018922193

Equilateral triangle [ side : 7.5 ]
Area : 24.356964481437334
``````
``````#  Python 3 Program
#  Calculate area of equilateral triangle
import math
class EquilateralTriangle :
# Calculate area of equilateral triangle by given side
def equilateral_triangle(self, side) :
# Calculate area of equilateral triangle
area = (math.sqrt(3) / 4) * (side * side)
# Display the result of right angle triangle area
print(" Equilateral triangle [ side : ", side , end = " ] ")
print("\n Area : ", area ,"\n")

def main() :
obj = EquilateralTriangle()
# Test Cases
obj.equilateral_triangle(5)
obj.equilateral_triangle(10)
obj.equilateral_triangle(7.5)

if __name__ == "__main__": main()``````

#### Output

`````` Equilateral triangle [ side :  5 ]
Area :  10.825317547305483

Equilateral triangle [ side :  10 ]
Area :  43.30127018922193

Equilateral triangle [ side :  7.5 ]
Area :  24.356964481437334
``````
``````#  Ruby Program
#  Calculate area of equilateral triangle
class EquilateralTriangle

# Calculate area of equilateral triangle by given side
def equilateral_triangle(side)

# Calculate area of equilateral triangle
area = (Math.sqrt(3) / 4) * (side * side)
# Display the result of right angle triangle area
print(" Equilateral triangle [ side  : ", side ," ] ")
print("\n Area  : ", area ,"\n\n")
end
end
def main()

obj = EquilateralTriangle.new()
# Test Cases
obj.equilateral_triangle(5)
obj.equilateral_triangle(10)
obj.equilateral_triangle(7.5)
end
main()``````

#### Output

`````` Equilateral triangle [ side  : 5 ]
Area  : 10.825317547305483

Equilateral triangle [ side  : 10 ]
Area  : 43.30127018922193

Equilateral triangle [ side  : 7.5 ]
Area  : 24.356964481437334

``````
``````// Scala Program
// Calculate area of equilateral triangle
class EquilateralTriangle
{
//Calculate area of equilateral triangle by given side
def equilateral_triangle(side: Double): Unit = {
//Calculate area of equilateral triangle
var area: Double = ((Math.sqrt(3) / 4)) * (side * side);
//Display the result of right angle triangle area
print(" Equilateral triangle [ side : " + side + " ] ");
print("\n Area : " + area + "\n\n");
}
}
object Main
{
def main(args: Array[String]): Unit = {
var obj: EquilateralTriangle = new EquilateralTriangle();
//Test Cases
obj.equilateral_triangle(5);
obj.equilateral_triangle(10);
obj.equilateral_triangle(7.5);
}
}``````

#### Output

`````` Equilateral triangle [ side : 5.0 ]
Area : 10.825317547305483

Equilateral triangle [ side : 10.0 ]
Area : 43.30127018922193

Equilateral triangle [ side : 7.5 ]
Area : 24.356964481437334
``````
``````// Swift Program
// Calculate area of equilateral triangle
import Foundation
class EquilateralTriangle
{
//Calculate area of equilateral triangle by given side
func equilateral_triangle(_ side: Double)
{
//Calculate area of equilateral triangle
let area: Double = (sqrt(3) / 4) * (side * side);
//Display the result of right angle triangle area
print(" Equilateral triangle [ side : ", side ,"]");
print(" Area : ", area ,"\n");
}
}
func main()
{
let obj: EquilateralTriangle = EquilateralTriangle();
//Test Cases
obj.equilateral_triangle(5);
obj.equilateral_triangle(10);
obj.equilateral_triangle(7.5);
}
main();``````

#### Output

`````` Equilateral triangle [ side :  5.0 ]
Area :  10.8253175473055

Equilateral triangle [ side :  10.0 ]
Area :  43.3012701892219

Equilateral triangle [ side :  7.5 ]
Area :  24.3569644814373
``````

## Output Explanation

The provided code runs three test cases and calculates the areas of equilateral triangles with different side lengths. The output includes the triangle's side length and the corresponding calculated areas.

## Time Complexity

The time complexity of this code is O(1) for each test case. The calculations involve basic arithmetic operations and a square root computation, which take constant time. Therefore, the overall time complexity remains constant for each test case.

## Comment

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