Abstract: With drawing, a changing parabold is formed by the two projective line pencils
formed. If the five vertexes of a pentagon are on a parabold, another parabold formed by a similar
pentagon is similar to this one. In order to draw elliptic parabolaid using computer, a series of
parallel cutting planes can be used which are similar parabolds to show the curves. This is referred
to as cutting layers method.

Key words: projective line pencils, similar parabold, elliptic paraboloid, cutting layer
method