Hypotenuse Calculations

Define a function called hypotenuse that calculates the length of the hypotenuse of a right angle triangle when the other two side are given.
Take two argument of type double and return the hypotenuse as a double.

/*
   title: hypotenuseCalculation
   author: aeriqusyairi
   date: Jan23 2012
*/
#include<stdio.h>
#include<math.h>

double hypotenuse(double, double);

int main(){
   double firstSide = 0, secondSide = 0, hypo = 0;
   
   printf("Enter the side of a right triangle\nto calculate its corresponding hypotenuse...\n");
   printf("Side 1:");
   scanf("%lf", &firstSide);
   printf("Side 2:");
   scanf("%lf", &secondSide);
   
   hypo = hypotenuse(firstSide, secondSide);
   
   printf("The hypotenuse of a right triangle with %.2lf and %.2lf\nas the other 2 side is %.2lf\n",
    firstSide, secondSide, hypo); 
   system("pause");
   return 0;     
}

double hypotenuse(double a, double b){
   double c;
   return sqrt((a * a) + (b * b));        
}