# C Program to Find Third Angle of a Triangle

Here is a C program find third angle of triangle, given other two angles of triangle. 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.

#### Required Knowledge

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

```#include <stdio.h>
#define ANGLE_SUM 180

int main() {
float a1, a2, a3;

printf("Enter Two Angles of a Triangle\n");
scanf("%f %f", &a1, &a2);

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
```

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