Why is my output returning random values for the variables time and height? Looking for guidance rather then straight answer.

#include <stdio.h>
#include <math.h>
#define G 32

int main(){
    int i=0, t=1, distance, D=(1/2)*G* pow(1,2), height=distance-D;

    printf("What is the height of the dragon's nest in feet?\n ");
    scanf("%d", &distance);
    printf("Time\tAltitude\n");

        if (distance<= 0)
            printf("0\t0\n");

        while (distance>0) {
            D=distance-D;
            printf("%d\t%d.\n",t, D);
            }

return 0;
}