Steve's Hyperbolic Tools Page
There are many models of hyperbolic geometry. Three common models are the Poincaré disk model, the the Poincaré half-plane model, and the Beltrami-Klein model. Within those models, we often want to perform standard constructions, such as bisecting angles, dropping perpendiculars, or drawing circles. However, in the non-Euclidean models, the constructions are not the same constructions as in Euclidean geometry. For example, in the Poincaré models, "lines" are defined to be arcs of certain circles.
On this and other linked pages can be found Geometer's Sketchpad scripts which automate 10 "standard" non-Euclidean constructions in the three models:
| 1. | Construct a non-Euclidean line, given two points on the line. |
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| 2. | Construct a non-Euclidean line segment, given the endpoints of the segment. |
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| 3. | Measure the length of a non-Euclidean line segment. |
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| 4. | Calculate the measure of an angle. |
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| 5. | Construct the bisector of a given angle. |
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| 6. | Construct a perpendicular to a given line through a given point on the line. |
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| 7. | Construct a perpendicular to a given line through a given point not on the line. |
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| 8. | Construct the perpendicular bisector of a non-Euclidean line segment. |
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| 9. | Construct a circle, given its center and a point on the circle. |
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| 10. | Construct a circle, given its center and two points determining the radius of the circle. |
Contents
- scripts.pdf: A description of the hyperbolic construction tools.
This file is in .pdf format and requires a reader
such as Adobe Acrobat, which can be found
here.
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How to install and use the tools.
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Links to others' work.
- Teaching Ideas: Some very brief ideas on ways to use the tools in the classroom. For more teaching ideas, you might want to look at the article "The Hyperbolic Toolbox" that I wrote for the Journal of Online Mathematics and its Applications.
Links to Others Work - Good Stuff!
Many others have created tools for hyperbolic constructions using dynamic geometry software. Here are links (last checked in April 2009) to some of their work.
- Alexander and Finzer's Geometer's Sketchpad scripts for constructions in the Poincaré disk.
- Bochaca's more recent Geometer's Sketchpad scripts for constructions in the Poincaré half-plane. The page includes a link to Bennett's earlier half-plane tools.
- Peil's Geometer's Sketchpad scripts for constructions in the Poincaré half-plane.
- David Flesner's Cabri Geometry scripts for constructions in the Klein Disk Model.