Program to draw a circle using Trigonometric Method

 # include <iostream.h>
 # include <graphics.h>
 # include    <conio.h>
 # include     <math.h>

 void show_screen( );

 void trigonometric_circle(const int,const int,const int);

 int main( )
    {
       int driver=VGA;
       int mode=VGAHI;

       int h=0;
       int k=0;
       int r=0;

       do
      {
         show_screen( );

         gotoxy(8,10);
         cout<<\"Central Point of the Circle : (h,k) :\";

         gotoxy(8,11);
         cout<<\"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ\";

         gotoxy(12,13);
         cout<<\"Enter the value of h = \";
         cin>>h;

         gotoxy(12,14);
         cout<<\"Enter the value of k = \";
         cin>>k;

         gotoxy(8,18);
         cout<<\"Radius of the Circle : r :\";

         gotoxy(8,19);
         cout<<\"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ\";

         gotoxy(12,21);
         cout<<\"Enter the value of r = \";
         cin>>r;

         initgraph(&driver,&mode,\"..\\\\Bgi\");

         setcolor(15);
           trigonometric_circle(h,k,r);

         setcolor(15);
           outtextxy(110,460,\"Press <Enter> to continue or any other key to exit.\");

         int key=int(getch( ));

         if(key!=13)
        break;
      }
       while(1);

       return 0;
    }


 //---------------------  trigonometric_circle( )  -----------------------//


 void trigonometric_circle(const int h,const int k,const int r)
    {
       int color=getcolor( );

       float x=0;
       float y=r;
       float angle=0;
       float range=M_PI_4;

       do
      {
         putpixel((int)(h+x+0.5),(int)(k+y+0.5),color);
         putpixel((int)(h+y+0.5),(int)(k+x+0.5),color);
         putpixel((int)(h+y+0.5),(int)(k-x+0.5),color);
         putpixel((int)(h+x+0.5),(int)(k-y+0.5),color);
         putpixel((int)(h-x+0.5),(int)(k-y+0.5),color);
         putpixel((int)(h-y+0.5),(int)(k-x+0.5),color);
         putpixel((int)(h-y+0.5),(int)(k+x+0.5),color);
         putpixel((int)(h-x+0.5),(int)(k+y+0.5),color);

         angle+=0.001;

         x=(r*cos(angle));
         y=(r*sin(angle));
      }
       while(angle<=range);
    }


 //--------------------------  show_screen( )  ---------------------------//


 void show_screen( )
    {
       restorecrtmode( );
       textmode(C4350);

       cprintf(\"\\n********************************************************************************\");
       cprintf(\"***************************-                        -***************************\");
       cprintf(\"*--------------------------- \");

       textbackground(1);
       cprintf(\" Trigonometric Method \");
       textbackground(8);

       cprintf(\" ---------------------------*\");
       cprintf(\"*-*************************-                        -*************************-*\");
       cprintf(\"*-****************************************************************************-*\");

       for(int count=0;count<42;count++)
      cprintf(\"*-*                                                                          *-*\");

       gotoxy(1,46);
       cprintf(\"*-****************************************************************************-*\");
       cprintf(\"*------------------------------------------------------------------------------*\");
       cprintf(\"********************************************************************************\");

       gotoxy(1,2);
    }