In this C program, we will learn about how to check whether a triangle is valid or not given the length of three sides of triangle. A triangle is a valid triangle, If and only If, the sum of any two sides of a triangle is greater than the third side.

For Example, let A, B and C are three sides of a triangle. Then, A + B > C, B + C > A and C + A > B.

#### Required Knowledge

## C program to check whether a triangle is valid, given sides of triangle

#include <stdio.h> int main() { int side1, side2, side3; printf("Enter Length of Sides of a Triangle\n"); scanf("%d %d %d", &side1, &side2, &side3); if((side1 + side2 > side3)&&(side2 + side3 > side1) &&(side3 + side1 > side2)) { printf("It is a Valid Triangle\n"); } else { printf("It is an invalid Triangle"); } return 0; }Output

Enter Length of Sides of a Triangle 10 20 20 It is a Valid Triangle

Enter Length of Sides of a Triangle 10 20 40 It is an invalid Triangle

**Related Topics**