# C Program to find Area of an Equilateral Triangle

In this tutorial, i am going to show you how to find or calculate area of equilateral Triangle with the help of standard formula, function and pointer in c programs.

## All C Programs and Algorithm to Find Area of Equilateral Triangle

• Algorithm to Find Area of a Equilateral Triangle
• C Program to Find Area of a Equilateral Triangle using sqrt
• C Program to Find Area of a Equilateral Triangle using Function
• C Program to Find Area of a Equilateral Triangle using Pointer

### Algorithm to Find Area of a Equilateral Triangle

Follow the below given algorithm to write a program to find the area of a equilateral Triangle; as follows:

1. Take input side of triangle. Store it in variable.
2. Calculate area of an Equilateral triangle using `(sqrt 3)/4 * a^2`
3. Finally, print the value of Area of an Equilateral triangle.

### C Program to Find Area of a Equilateral Triangle using sqrt

```#include<math.h>
int main()
{
float area,a;
printf("enter side of the triangle: ");
scanf("%f",&a);

area=(sqrt(3)/4)*a*a;
printf("AOET:%f\n",area);
return 0;
}```

The result of the above c program; as follows:

```enter side of the triangle: 5
AOET:10.825317```

### C Program to Find Area of a Equilateral Triangle using Function

```#include<stdio.h>
#include<math.h>
float area(float a)
{
float Ar=(sqrt(3)/4)*a*a;
return Ar;
}

int main()
{
float Ar,a;
printf("enter side of the triangle: ");
scanf("%f",&a);

Ar=area(a);
printf("AOET: %f\n",Ar);
return 0;
}```

The result of the above c program; as follows:

```enter side of the triangle: 7
AOET: 21.217623```

### C Program to Find Area of a Equilateral Triangle using Pointer

```#include<stdio.h>
#include<math.h>
float area(float *a,float *Ar)
{

*Ar=(sqrt(3)/4)* (*a) * (*a);

}

int main()
{
float a,Ar;
printf("enter side: ");
scanf("%f",&a);
area(&a,&Ar);
printf("AOET: %f\n",Ar);
return 0;
}```

The result of the above c program; as follows:

```enter side: 6
AOET: 15.588457```