C program to draw circles in circles

This program draws circles in circles in two different colors.

C programming code
#include<graphics.h>
#include<conio.h>
#include<dos.h>

main()
{
   int gd = DETECT, gm, x, y, color, angle = 0;
   struct arccoordstype a, b;

   initgraph(&gd, &gm, "C:\\TC\\BGI");
   delay(2000);

   while(angle<=360)
   {
      setcolor(BLACK);
      arc(getmaxx()/2,getmaxy()/2,angle,angle+2,100);
      setcolor(RED);
      getarccoords(&a);
      circle(a.xstart,a.ystart,25);
      setcolor(BLACK);
      arc(getmaxx()/2,getmaxy()/2,angle,angle+2,150);
      getarccoords(&a);
      setcolor(GREEN);
      circle(a.xstart,a.ystart,25);
      angle = angle+5;
      delay(50);
   }

   getch();
   closegraph();
   return 0;
}