code help please! (c language )

i wrote a code and its not outputting what i want

#include <stdio.h>
int triangle(int n);
int factorial(int n);
int choose(int n, int r);

int main(int argc, char **argv)
{
int row, x, y, z;

printf("Enter the number of rows:");
scanf("%d", &row);

while (row>=0 && row<=13){
for(x=0; x<row; x++){
for(y=row-x; y>0; y--){
printf(" ");
}
for(z=0;z<=x;z++){
printf("%d ", triangle(row));
}
printf("\n");
}
printf("Enter the number of rows:");
scanf("%d", &row);

}
return 0;
}

int triangle(int n){

int factorial(int n){
if (n<=1){
return 1;
}
else
return n * factorial(n-1);
}
int choose(int n, int r){
return factorial(n)/(factorial(r)*factorial(n-r));
}
return 0;
}

this is the code and Its supposed to be outputting Pascal triangle but it only outputting zero

my c is rusty but as far as I can see your triangle function includes a factorial function and a choose function, but never calls the choose function - it just returns 0 all the time. Stick some debugging statements into your functions to see what is being called, when, and with what parameters.

thank you for the help but I'm kind of new to c language so I mostly understood what you said but would be too much if i asked for an example code of what you're saying?