analog clock c code for turbo

#include <graphics.h>
#include <stdlib.h>
#include <conio.h>
#include <dos.h>
#include <math.h>

#define pi 3.1415926535

void drawClock();
void drawHourHand(int, int, int);
void drawMinuteHand(int, int, int);
void drawSecondHand(int, int, int);

int main()
{
    int gd = DETECT, gm;
    int hr, min, sec;

    initgraph(&gd, &gm, "C:\\Turboc3\\BGI");

    while (!kbhit())
    {
        struct tm *ptr;
        time_t lt;
        lt = time(NULL);
        ptr = localtime(&lt);

        hr = ptr->tm_hour;
        min = ptr->tm_min;
        sec = ptr->tm_sec;

        drawClock();
        drawHourHand(hr, min, sec);
        drawMinuteHand(min, sec, hr);
        drawSecondHand(sec, min, hr);

        delay(1000);
        cleardevice();
    }

    closegraph();
    return 0;
}

void drawClock()
{
    setcolor(RED);
    circle(250, 250, 200);

    for (int i = 0; i < 360; i += 6)
    {
        if (i % 30 == 0)
        {
            setcolor(WHITE);
            line(250 + (180  cos(i  (pi / 180))), 250 + (180  sin(i  (pi / 180))),
                 250 + (200  cos(i  (pi / 180))), 250 + (200  sin(i  (pi / 180))));
        }
        else
        {
            setcolor(YELLOW);
            line(250 + (190  cos(i  (pi / 180))), 250 + (190  sin(i  (pi / 180))),
                 250 + (200  cos(i  (pi / 180))), 250 + (200  sin(i  (pi / 180))));
        }
    }
}

void drawHourHand(int hr, int min, int sec)
{
    int angle;
    angle = 90 - (30 * hr + min / 2);

    setcolor(WHITE);
    line(250, 250, 250 + 50  cos(angle  (pi / 180)), 250 - 50  sin(angle  (pi / 180)));
}

void drawMinuteHand(int min, int sec, int hr)
{
    int angle;
    angle = 90 - (6 * min + sec / 10);

    setcolor(YELLOW);
    line(250, 250, 250 + 70  cos(angle  (pi / 180)), 250 - 70  sin(angle  (pi / 180)));
}

void drawSecondHand(int sec, int min, int hr)
{
    int angle;
    angle = 90 - 6 * sec;

    setcolor(GREEN);
    line(250, 250, 250 + 90  cos(angle  (pi / 180)), 250 - 90  sin(angle  (pi / 180)));
}