### C program to find the third angle of a triangle :

In this tutorial, we will learn how to find the *third* angle of a triangle if the *first* and *second* angle is given.

We know that the sum of all three angles of a triangle is *180* degree. So, to find the third angle, we will *subtract* the sum of two angles from *180*. Let’s take a look at the program :

### C Program code :

#include #define SUM 180 int main(){ //1 float firstAngle,secondAngle,thirdAngle; //2 printf("Enter first and second angle of the triangle : "); scanf("%f %f",&firstAngle,&secondAngle); //3 thirdAngle = SUM - (firstAngle + secondAngle); //4 printf("You have entered %f and %f\n",firstAngle,secondAngle); printf("Third Angle is : %f \n",thirdAngle); }

### Explanation :

*The commented numbers above **indicate** the steps number below :*

1. First, create three float variables to store all *three angles*.

2. Ask the user to enter the *first* and *second* angle of the triangle. And store it in variables *firstAngle* and *secondAngle*.

3. Now, calculate the third angle and store the value in variable *thirdAngle*.

4. Print all angles: *firstAngle,secondAngle and thirdAngle*

### Sample Outputs :

Enter first and second angle of the triangle : 120 30 You have entered 120.000000 and 30.000000 Third Angle is : 30.000000 Enter first and second angle of the triangle : 20 30 You have entered 20.000000 and 30.000000 Third Angle is : 130.000000 Enter first and second angle of the triangle : 13.5 12.5 You have entered 13.500000 and 12.500000 Third Angle is : 154.000000