# PoincaréDraw

Out of nothing I have created a strange new universe.
János Bolyai  (1802 - 1860)

A java version of PoincaréDraw is being developed. Please notify me if you are interested in previewing it when it is ready.

PoincaréDraw is a dynamic, interactive computer program used to make compass and straightedge constructions in the Poincaré disk model of the hyperbolic plane.  Here are some images from the program.  Click on them for larger (and clearer) versions.

Opening Screen             The Poincaré Disk

Two Hyperbolic Lines Passing Though P Parallel to Line AB!
A Hyperbolic Triangle
A Hyperbolic Circle with Center C and Diameter AB
The Common Perpendicular to Two Parallel Lines

The Altitudes of a Triangle Are Concurrent
So are the Perpendicular Bisectors of the Sides
Or Are They?!?

What you can't see from this web page is that the points that have been plotted can be moved around and the figures depending on them move with them!   This is similar to The Geometer's Sketchpad, a popular program for doing Euclidean geometry, published by Key Curriculum Press.

PoincaréDraw is a DOS program.  It works well in Windows when run full-screen.

Download PoincaréDraw, Version 2.0, January 1998.  Zipped file contains program and documentation files.
Note: Beginning in October 1999 the zipped file contains two slightly different versions of PoincaréDraw, PDraw20.exe and PDraw20a.exe. A bug in one of Turbo Pascal's library routines causes a "Runtime error 200: Division by zero" when PDraw20.exe is run on a machine with a Pentium III processor.  If this happens, you should use PDraw20a.exe instead. PDraw20a.exe may run more slowly than PDraw20.exe on machines that run both. For more information about this bug (which affects many programs written in Turbo Pascal), see Borland/Inprise and Intel support documentation.

PoincaréDraw is Copyrighted 1998 by Robert L. Foote.

Permission is granted to make and distribute copies, provided the program and documentation files are copied and distributed as a package and no changes are made to either.  Instructors using PoincaréDraw in a class are requested to notify Robert Foote.

PoincaréDraw was designed by Robert Foote and programmed by Nathan Fouts (Wabash Class of '97).  Initial development took place during the summer of 1995.  Further work during the spring and summer of 1997 was funded by the National Science Foundation, Division of Undergraduate Education grant number DUE-9554636 as a follow-up to the conference "Exploring Undergraduate Algebra & Geometry with Technology" held at DePauw University, June 1996.

Dynamic, Interactive Hyperbolic Geometry with PoincaréDraw is a paper written for the proceedings of the conference "Exploring Undergraduate Algebra & Geometry with Technology" held at DePauw University, June 1996.