GL_POLYGON Example In OpenGl

#include <GL/glut.h>      
void display()
{
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(1.0,1.0,0.0);
glBegin(GL_POLYGON);
glVertex3f(0.1, 0.1,0.0);
glVertex3f(0.6, 0.1,0.0);
glVertex3f(0.8,0.3,0.0);
glVertex3f(0.6,0.6,0.0);
glVertex3f(0.1,0.6,0.0);
glVertex3f(0.0,0.3,0.0);
glEnd();
glFlush();
}
void init()
{
glClearColor(0.0,0.5,0.2,0.8);
}
int main(int argc, char** argv)
{
glutCreateWindow("simple 3D");
glutDisplayFunc(display);
init();
glutMainLoop();
}