Nonlinear Tessellations

Construction

Step 2

Find the midpoint W of the segment OB from O, the center of the hexagon, to B, the midppoint of one of the sides.
Draw the circle S with center W and passing through O.
Draw the circle U with center B and with diameter the side of the hexagon.
Draw the circle C with center O and passing through the intersections of the circles S and U.
This circle C is the boundary of the Poincare disc.
Three features of this construction are important to note.
* From a previous construction, the circles C and U are orthogonal.
* The cirlce U and segment OB are orthogonal.
The circle U intersects segment AO at 30 degrees. This requires some effort.
We have constructed the hyperbolic triangle with angles 30, 30, and 90.

Return to construction.