C Program to Find Third Angle of a Triangle

  • Write a C program find third angle of triangle.

Required Knowledge

We will first take two angles of a triangle as input from user using scanf function. To find the third angle of triangle we will use below mentioned angle sum property of a triangle.

Sum of all internal angles of a triangle is 180 degrees.

  • A + B + C = 180

Where A, B and C are the three internal angles of a triangle.

C program to find third angle of a triangle

C Program to Find Third Angle of a Triangle

/* 
 * Given two angles of a triangle, Here is the 
 * C program to find third angle
 */ 
   
#include <stdio.h>  
#define ANGLE_SUM 180
 
int main() {
 /* Three angles of a triangle */
    float a1, a2, a3;  
   
    /* 
     * Take two angles as input from user 
     */ 
    printf("Enter Two Angles of a Triangle\n");  
    scanf("%f %f", &a1, &a2);  
   
    /* Sum of all three angles of a triangle is 180 degrees */ 
    a3 = ANGLE_SUM - (a1 + a2);  
   
    printf("Third Angle = %0.4f", a3);  
   
    return 0;  
}

Output

Enter Two Angles of a Triangle
30 60
Third Angle = 90.0000