Pappus's Hexagon Theorem

If , , and are three points on one Line, , , and are three points on another Line, and meets at , meets at , and meets at , then the three points , , and areCollinear. Pappus's hexagon theorem dual to Desargues' Theorem according to the Duality Principle ofProjective Geometry.

References

Coxeter, H. S. M. and Greitzer, S. L. Geometry Revisited. Washington, DC: Math. Assoc. Amer., pp. 73-74, 1967.

Ogilvy, C. S. Excursions in Geometry. New York: Dover, pp. 92-94, 1990.

Pappas, T. ``Pappus' Theorem & the Nine Coin Puzzle.'' The Joy of Mathematics. San Carlos, CA: Wide World Publ./Tetra, p. 163, 1989.

• Distribution (Functional)
• Distribution Parameter
• Distribution (Statistical)
• Distributive
• Distributive Lattice
• Disymmetric
• Ditrigonal Dodecadodecahedron
• Ditrigonal Dodecahedron
• Divergence
• Divergenceless Field
• Divergence Tests
• Divergence Theorem
• Divergent Sequence
• Divergent Series
• Diversity Condition
• Divide
• Divided Difference
• Divine Proportion
• Divisibility Tests
• Divisible
• Division
• Division Algebra
• Division Lemma
• Division Ring
• Divisor