Grafika Komputer QUADS,RECTANGEL,and TRIANGEL

Dapat tugas grafika komputer dari Dosen STIKOM AK "Mizar Firdaus Tino" nih tentang buat quads, rectangel dan triangel. Yaa semoga bermanfaat buat kalian.
nih rumusnya kita pake C++ yah. . . belajar ini kita belajar vektor vektor lagi. Matematika lagi kepake lagi tuh koordinat (x,y) nya. hayoo lah cuss. .

#include <windows.h>
    #include <gl\gl.h>
    #include <gl\glu.h>
    #include <gl\glut.h>
   
//<<<<<<myInt>>>>>>>

    void myInt(void)
    {
    glClearColor(1.0,1.0,0.0,0.0);//background warna, dengan digit terakhir adalah alpha
    glColor3f(0.0f,0.0f,0.0f);
    glPointSize(4.0);
    glMatrixMode(GL_PROJECTION);//menentukan operasi matrix
    glLoadIdentity();
    gluOrtho2D(0.0,640.0,0.0,480.0);
    }

//<<<<<<<myDisplay>>>>>>>

    void myDisplay (void)
    {
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_QUADS);
    glColor3f (0.0,0.0,1.1);
    glVertex2i(90,40);
    glVertex2i(170,40);
    glVertex2i(200,100);
    glVertex2i(60,100);
     glVertex2i(70,30);
    glEnd();
    glFlush();
   
    glBegin(GL_TRIANGLES);
     glColor3f (1.0,0.0,1.0);
    glVertex2i(70,200);
    glVertex2i(20,100);
    glVertex2i(130,100);
    glColor3f (0.0,1.0,1.0);
    glVertex2i(130,100);
    glVertex2i(195,200);
    glVertex2i(70,200);
     glColor3f (0.0,0.1,0.1);
    glVertex2i(195,200);
    glVertex2i(240,100);
    glVertex2i(130,100);
    glEnd();
    glFlush();
   
    glBegin(GL_POLYGON);
    glColor3f (0.0,0.1,0.0);
    glVertex2i(70,200);
    glVertex2i(195,200);
    glVertex2i(195,280);
    glVertex2i(70,280);
   
    glEnd();
    glFlush();
}

   
     
     
   
   
//<<<<<<<main>>>>>>
    int main (int argc, char**argv)
    {
    glutInit(&argc, argv);//initialize the toolkit
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); //set display mode
    glutInitWindowSize(640,480); //set window size
    glutInitWindowPosition(100,150); //set window position on screen
    glutCreateWindow("heppy rianti"); //open the screen window
    glutDisplayFunc(myDisplay);//register redraw function
    myInt();
    glutMainLoop(); //go into a perpetual loop
    }