glBegin(GL_POLYGON);
glColor3f(1f,0f,0f);
glVertex3f(0,360+100,0);
glColor3f(0f,1f,0f);
glVertex3f(0,360+100,1000);
glColor3f(0f,0f,1f);
glVertex3f(0,360+100,10000);
glVertex3f(0,0-100,10000);
glColor3f(0f,1f,0f);
glVertex3f(0,0-100,1000);
glColor3f(1f,0f,0f);
glVertex3f(0,0-100,0);
glEnd();