A.
Gl.glBegin(Gl.GL_POINTS); { Gl.glVertex3d(-0.5, 0, 0); Gl.glVertex3d(0.5, 0, 0); Gl.glVertex3d(0, 0.5, 0); } Gl.glEnd();
B.
Gl.glBegin(Gl.GL_TRIANGLES); { Gl.glVertex3d(-0.5, 0, 0); Gl.glVertex3d(0.5, 0, 0); Gl.glVertex3d(0, 0.5, 0); } Gl.glEnd();
C.
Gl.glBegin(Gl.GL_QUADS); { Gl.glVertex3d(-0.5, 0, 0); Gl.glVertex3d(0.5, 0, 0); Gl.glVertex3d(0, 0.5, 0); } Gl.glEnd();