Called function work at printf but not at arithmetic statement

I made a struct Triangle and I made a function to calculate p(perimeter/2).
When I call the function inside printf it works.
But when I call the same function as a simple arithmetic statement it doesn’t work and gives me following error

called object 'p' is not a function or function pointer

Source code:

#include <stdlib.h>
typedef struct{
       int a, b, c;
} Triangle;
    
int perimeter (Triangle t){
    return t.a + t.b + t.c;
}
    
float p (Triangle t){
    return perimeter(t) / 2.0;
}
    
int main() {   
    Triangle t = {3, 4, 5};
    //float p = p(t);
    printf("p = %.2f\n",p(t));
    return 0;   
}

>Solution :

The line

float p = p(t);

defines a local variable p which shadows the global function p. This variable is of type float, so it is not a function or pointer.

Rename the variable to fix this.