C Program to find Area of a Triangle

Area of a triangle formula

Area of a triangle =  (base * height)/2

Additional,
Area of a triangle = square root of (s(s-a)(s-b)(s-c)) here a,b and c are sides of the triangle. s = (a+b+c)/2

Area of an equilateral triangle = (square root of (3) * side * side)/4

C Program to find the area of a triangle using base and height

This C program gets base and height as user inputs and computes the area of a triangle.

#include<stdio.h>                                                                
                                                                                
void main()                                                                     
{                                                                               
    int base, height, area=0;                                                   
    printf("\nFinds area of triangle using base and height");                   
    printf("\n-------------------------------------------");                    
    printf("\nEnter base: ");                                                   
    scanf("%d", &base);                                                         
    printf("Enter height: ");                                                   
    scanf("%d", &height);                                                       
                                                                                
    area = (base * height) / 2;                                                 
                                                                                
    printf("Area of triangle: %d", area);                                       
}                                                                      
                                                                                  

$ cc area-of-triangle.c 
$ ./a.out 

Finds area of triangle using base and height
-------------------------------------------
Enter base: 5
Enter height: 6
Area of triangle: 15

C Program to find the area of a triangle using triangle sides

This C program gets all the triangle sides as user inputs and computes the area of a triangle.

#include<stdio.h>                                                                
#include<math.h>
                                                                                
void main()                                                                     
{                                                                               
    int a, b, c, s;                                                             
    double area=0;                                                              
    printf("\nFinds area of triangle using triangle sides");                    
    printf("\n-------------------------------------------");                    
    printf("\nEnter side a: ");                                                 
    scanf("%d", &a);                                                            
    printf("Enter side b: ");                                                   
    scanf("%d", &b);                                                            
    printf("Enter side c: ");                                                   
    scanf("%d", &c);                                                            
                                                                                
    s = (a+b+c)/2;                                                              
    area = sqrt((double)(s*(s-a)*(s-b)*(s-c)));                                 
                                                                                
    printf("Area of triangle: %.2lf", area);                                      
}                                                                     
                                                                                  

$ cc area-of-triangle.c -o a.out -lm
$ ./a.out 

Finds area of triangle using triangle sides
-------------------------------------------
Enter side a: 6
Enter side b: 7
Enter side c: 8
Area of triangle: 15.49[

C Program to find the area of an equilateral triangle using triangle side

This C program gets all the triangle side as user input and computes the area of an equilateral triangle.

#include<stdio.h>                                                                
#include<math.h>
                                                                                
void main()                                                                     
{                                                                               
    int side;                                                                   
    double area=0;                                                              
    printf("\nFinds area of equilateral triangle using triangle side");         
    printf("\n-------------------------------------------");                    
    printf("\nEnter side: ");                                                   
    scanf("%d", &side);                                                         
                                                                                
    area = (double)((sqrt(3)*side*side)/4);                                     
                                                                                
    printf("Area of equilateral triangle: %.2lf", area);                        
}                                                                     
                                                                                  

$ cc area-of-triangle.c -o a.out -lm
$ ./a.out 

Finds area of equilateral triangle using triangle side
-------------------------------------------
Enter side: 8
Area of equilateral triangle: 27.71