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 <bits/stdc++.h> 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
<?php // PHP program to find area // and perimeter of equilateral triangle // Function to calculate Area // of equilateral triangle function area_equi_triangle( $side )
{ return sqrt(3) / 4 * $side * $side ;
} // Function to calculate Perimeter // of equilateral triangle function peri_equi_triangle( $side )
{ return 3 * $side ;
} // Driver Code $side = 4;
echo ( "Area of Equilateral Triangle: " );
echo (area_equi_triangle( $side ));
echo ( "\n" );
echo ( "Perimeter of Equilateral Triangle: " );
echo ( peri_equi_triangle( $side ));
// This code is contributed // by vt_m. ?> |
Javascript
<script> //Javascript program to find area
// and perimeter of equilateral triangle
// Function to calculate
// Area of equilateral triangle
function area_equi_triangle(side)
{
return (((Math.sqrt(3)) / 4) * side * side).toFixed(4);
}
// Function to calculate
// Perimeter of equilateral
// triangle
function peri_equi_triangle(side)
{
return 3 * side;
}
//Driver code
var side = 4;
document.write( "Area of Equilateral Triangle:" );
document.write(area_equi_triangle(side)+ "\n" );
document.write( "Perimeter of Equilateral Triangle:" );
document.write(peri_equi_triangle(side)+ "\n" );
//This code is contributed by shruti456rawal
</script> |
Output
Area of Equilateral Triangle: 6.9282 Perimeter of Equilateral Triangle: 12
Time Complexity: O(1)
Auxiliary Space: O(1)