Thread: right angle triangle help

I need to make a program which calculates whether or not a triangle is a right angle triangle based on the input of the 3 sides. heres my code wondering if anyone can point out the errors?

Code:

/* This program will calculate wether or not the values entered by a user consitute a right angle triangle*/

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
	float a, b, c;
		int sum;

	printf("please enter your values of length for the sides of your triangle.\n a and b will be the shorter sides while the value you enter for \nc must be the greatest length\n");
		printf(" enter a:\n");
			scanf("%f", &a);

		printf(" enter b:\n");
			scanf("%f", &b);

		printf(" enter c:\n");
			scanf("%d", &c);

sum = sqrt(a*a+b*b);

	if (sum == c)
	{
		printf("your values indicate the triangle is a right angle triangle\n");
	}

	else
	{
		printf("The values entered do not indicate a right angle triangle\n");
	}

	system ("pause");

	return 0;
}

thanks everyone comments were very helpful especially you adak. I made the necessary changes but im still left with the problem that it always returns that the triangles is not a right angle triangle. I am guessing its because the program wont round anything. Is there a way to make it accept only 2 significant figures? o and about the verbose description it's what was in the examples i was given by the prof so i figured I'd play it safe

I changed it to this. May not be exact but its accurate to within 0.1, so not too shabby.

Code:

/* This program will calculate whether or not the values entered by a user consitute a right angle triangle*/

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
	float a, b, c;
		float sum, difference;

	printf("please enter your values of length for the sides of your triangle.\n a and b will be the shorter sides while the value you enter for \nc must be the greatest length\n");
		printf(" enter a:\n");
			scanf("%f", &a);

		printf(" enter b:\n");
			scanf("%f", &b);

		printf(" enter c:\n");
			scanf("%f", &c);

	sum = sqrt((b*b)+(a*a));
	difference = c - sum;

	if (difference <= 0.1 )
	{
		printf("your values indicate the triangle is a right angle triangle\n");
	}

	else
	{
		printf("The values entered do not indicate a right angle triangle\n");
	}

	system ("pause");

	return 0;
}