2D Basic Transformations such as Translation, Rotation and Scaling in C Programming

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

void translate(int,int);
void scale(int,int);
void rotate(float);

void main()
{
 int ch;
 int gd=DETECT,gm;
 int tx,ty,sx,sy;
 float theta;
 initgraph(&gd,&gm,"c:\\tc\\bgi");
 setbkcolor(WHITE);
 setcolor(6);
 outtextxy (100,88,"Object.");
 rectangle(100,250,150,200);

 printf("---MENU---");
 printf("\n 1)Translate\n 2)Scale\n 3)Rotate");
 printf("\nEnter your choice: ");
 scanf("%d",&ch);
 cleardevice();

 switch(ch)
 {
  case 1:
    outtextxy(10,45,"Enter value of tx and ty:");
    scanf("%d %d",&tx,&ty);
    translate(tx,ty);
    break;
  case 2:
    outtextxy(10,45,"Enter the value of sx and sy:");
    scanf("%d%d",&sx,&sy);
    scale(sx,sy);
    break;
  case 3:
    outtextxy(10,50,"Enter the angle for rotation: ");
    scanf("%f",&theta);
    rotate(theta);
  break;
  default: printf("you have enterd wrong choice");
  break;
 }
 getch();
 closegraph();
}

void translate(int tx,int ty)
{
 setcolor(2);
 outtextxy(240,10,"TRANSLATION");
 outtextxy(238,20,"------------");
 rectangle(100,250,150,200);
 rectangle(100+tx,250+ty,150+tx,200+ty);
}

void scale(int sx,int sy)
{
 setcolor(2);
 outtextxy(240,10,"SCALING");
 outtextxy(238,20,"--------");
 rectangle(100,250,150,200);
 rectangle(100*sx,250*sy,150*sx,200*sy);
}

void rotate(float theta)
{
 int x1,x2,x3,x4;
 int y1,y2,y3,y4;
 int ax1,ax2,ax3,ax4,ay1,ay2,ay3,ay4;
 int refx,refy;
 theta=theta*(3.14/180);
 setcolor(2);
 outtextxy(240,10,"ROTATE");
 outtextxy(238,20,"-------");
 refx=100;
 refy=100;

 x1=100;
 y1=100;
 x2=150;
 y2=100;
 x3=150;
 y3=150;
 x4=100;
 y4=150;

 ax1=refy+(x1-refx)*cos(theta)-(y1-refy)*sin(theta);
 ay1=refy+(x1-refx)*sin(theta)+(y1-refy)*cos(theta);

 ax2=refy+(x2-refx)*cos(theta)-(y2-refy)*sin(theta);
 ay2=refy+(x2-refx)*sin(theta)+(y2-refy)*cos(theta);

 ax3=refy+(x3-refx)*cos(theta)-(y3-refy)*sin(theta);
 ay3=refy+(x3-refx)*sin(theta)+(y3-refy)*cos(theta);

 ax4=refy+(x4-refx)*cos(theta)-(y4-refy)*sin(theta);
 ay4=refy+(x4-refx)*sin(theta)+(y4-refy)*cos(theta);
 rectangle(100,150,150,100);
 line(ax1,ay1,ax2,ay2);
 line(ax2,ay2,ax3,ay3);
 line(ax3,ay3,ax4,ay4);
 line(ax4,ay4,ax1,ay1);
}

OUTPUT