Write a C program to check whether a triangle is valid or not if angles are given using if else. How to check whether a triangle can be formed or not, if its angles are given using if else in C programming. Logic to check triangle validity if angles are given in C program.
Example
Input
Input
Input first angle: 60 Input second angle: 30 Input third angle: 90
Output
The triangle is valid
Required knowledge
Basic C programming, Relational operators, If else
Property of a triangle

A triangle is said to be a valid triangle if and only if sum of its angles is 180 °.
Logic to check triangle validity if angles are given
Step by step descriptive logic to check whether a triangle can be formed or not, if angles are given.
- Input all three angles of triangle in some variable say angle1, angle2 and angle3.
- Find sum of all three angles, store sum in some variable say
sum = angle1 + angle2 + angle3. - Check
if(sum == 180)then, triangle can be formed otherwise not. In addition, make sure angles are greater than 0 i.e. check condition for anglesif(angle1 > 0 && angle2 > 0 && angle3 > 0).
Program to check triangle validity when angles are given
/** * C program to check whether a triangle is valid or not if angles are given */ #include <stdio.h> int main() { int angle1, angle2, angle3, sum; /* Input all three angles of triangle */ printf("Enter three angles of triangle: \n"); scanf("%d%d%d", &angle1, &angle2, &angle3); /* Calculate sum of angles */ sum = angle1 + angle2 + angle3; /* * If sum of angles is 180 and * angle1, angle2, angle3 is not 0 then * triangle is valid. */ if(sum == 180 && angle1 > 0 && angle2 > 0 && angle3 > 0) { printf("Triangle is valid."); } else { printf("Triangle is not valid."); } return 0; }Output
Enter three angles of triangle: 30 60 90 Triangle is valid.
Happy coding 😉