program to draw Circle Using Trignometric functions.

Code for header file “Myheader.h”

#include <dos.h>

#include <graphics.h>

#include<math.h>

int theta;

void draw(int,int,int,int);

void cir(int x1, int y1, int r)

{

for( th=0;th<90;th++)

 {

 int  X=r*cos(th);

 int  Y=r*sin(th);

 drawCircle(x1,y1,X,Y);

  }

}

void draw(int xc,int yc,int x,int y)

{

putpixel(xc+x, yc+y, RED);

putpixel(xc-x, yc+y, RED);

putpixel(xc+x, yc-y, RED);

putpixel(xc-x, yc-y, RED);

putpixel(xc+y, yc+x, RED);

putpixel(xc-y, yc+x, RED);

putpixel(xc+y, yc-x, RED);

putpixel(xc-y, yc-x, RED);

}

Code For Main Program

#include<conio.h>

#include <dos.h>

#include <graphics.h>

#include"z:\Myheader.h"

void main()

{

int xc, yc, r,theta;

int gd = DETECT, gm;

initgraph(&gd, &gm, "");

printf("Enter center coordinates of circle (Xc,Yc): ");

scanf("%d %d", &xc, &yc);

printf("Enter radius of circle: ");

scanf("%d", &r);

cir(xc, yc, r);

getch();

}

OUTPUT :