Experiment in Hyperbolic Geometry
Directions:  Point your internet browser to Non Euclid   You may either download NonEuclid.zip or run the appet "NonEuclid".  Do the following.
   - In the PoincarŽ model, follow Euclid's proof of proposition 1 to construct an equilateral triangle ABC. 
      
         - Draw line segment AB
         
 - Draw circle with center A and radius AB
         
 - Draw circle with center B and radius BA
         
 - Construct the points of intersection C, D
         
 - Draw line segments, AC, BC
      
 
    - Measure triangle ABC
   
 - Move points A and B around the space and answer the following questions:
      
         - Are the sides of your triangle always equal?
         
 - Are the angles of your triangle always equal?
         
 - What is the largest angle sum possible?  What does the triangle look like when you get close to this sum?
         
 - What is the smallest angle sum possible?  What does the triangle look like when you get close to this sum?
      
 
    - Change to the half plane model of hyperbolic geometry and repeat steps 1, 2, 3.
 
Last Update: October 4, 2006
Ronald K. Smith
Graceland University
Lamoni, IA 50140
rsmith@graceland.edu