how to verify if its a triangle in c

1/**
2 * C program to check whether a triangle is valid or not if its sides are given
3 */
4
5#include <stdio.h>
6
7int main()
8{
9    int side1, side2, side3;
10
11    /* Input three sides of a triangle */
12    printf("Enter three sides of triangle: \n");
13    scanf("%d%d%d", &side1, &side2, &side3);
14    
15    if((side1 + side2) > side3)
16    {
17        if((side2 + side3) > side1)
18        {
19            if((side1 + side3) > side2) 
20            {
21                /*
22                 * If side1 + side2 > side3 and
23                 *    side2 + side3 > side1 and
24                 *    side1 + side3 > side2 then
25                 * the triangle is valid.
26                 */
27                printf("Triangle is valid.");
28            }
29            else
30            {
31                printf("Triangle is not valid.");
32            }
33        }
34        else
35        {
36            printf("Triangle is not valid.");
37        }
38    }
39    else
40    {
41        printf("Triangle is not valid.");
42    }
43
44    return 0;
45}

1/* 
2     formula is : any of 2 side is must be bigger than the third side of a triangle.
3 */
4#include <stdio.h>
5int main()
6{
7     double side1, side2, side3;
8     scanf("%lf %lf %lf", &side1, &side2, &side3);
9
10     if (side1 + side2 > side3 && side2 + side3 > side1 && side1 + side3 > side2) // applying formula
11     {
12          printf("Yes. It can be a triangle\n");
13     }
14     else
15     {
16          printf("Yes. It can't be a triangle\n");
17     }
18     return 0;
19}