Right Angle Triangle Checker C program

The below code checks whether a triangle is right angled or not by taking input the lengths of all three sides.

Logic: By Pythagoras theorem, 

(hypotenuse)^2 = (base)^2+(perpendicular)^2

If the input data satisfies the above equation then the triangle will be a right angle triangle.

Code: 

#include <stdio.h>
#include <conio.h>

void main()
{
    char x,check;

    float first,second,third;

    printf("This program checks wheater the trianle is a right angle triangle or not\n\nEnter the lenght of first side:");
    scanf("%f",&first);
    printf("Enter the length of second side:");
    scanf("%f",&second);
    printf("Enter the length of third side:");
    scanf("%f",&third);

    if(first==0&&second==0&&third==0)
        printf("invalid input");
    else
        {
      if((first*first)==(second*second)+(third*third))
        printf("The triangle is an right angle triangle");
      else if((second*second)==(first*first)+(third*third))
        printf("The triangle is an right angle triangle");
      else if((third*third)==(second*second)+(first*first))
        printf("The triangle is an right angle triangle");
      else
        printf("The triangle is not an right angle triangle");
        }
     printf("\n\n(*_*) Would you like to run again...(Y/N)");
     scanf(" %c", &check);
     if(check=='Y'||check=='y')
            {
                system("cls");
                main();
            }
      printf("\npress any key to continue");
      getch();

}
 

Monday, 21 April 2014