3. Triangle and Inscribed Angle | (07/06/25) Not constant, Absolute unit length (1) |
4. Model | Make a disk model, Open and closed |
5. Disk and Hyperboloid | Interchangeable relations |
6. Equivalent Deformation, | |
Comparison with Elliptic Geometry (1) | (07/04/14) Locus of vertex of a triangle |
7. Parallel Angle | What is it? |
8. Lobachevsky's Postulate | (07/07/19) How was it found? Can we draw infinity? |
9. Distance and Angle, Hyperbolic Trigonomery | (07/06/22) Dependent relations, Absolute unit length (2) |
10. Equidistant Lines (1) | How does it look? Parallel curves |
11. Ultraparallel Lines | Common perpendicular |
12. Tiling (tessellation) | (07/05/01) Reflection, Ideal triangle |
13. Parallel Translation (1) | Get locus by reflection |
14. Circle | Cutting hemisphere |
15. Move Circle | Toward infinity |
16. Extending Disk Model | (07/07/02) To get real hyperbolic plane |
17. Horocycle (1) | Hemisphere, Translation, Equidistant lines (2) |
18. Pseudo-sphere (1) | Is hyperbolic surface realized? |
19. Upper Half-plane (1) | Relation with Poincare's disk, Digitized model |
20. Horocycle (2) | Poincare's disk, Upper Half-plane (2) |
21. Metric, Break Pythagorean Theorem | (07/06/13) Riemann, Mercator, Pseudo-sphere (2) |
22. Mutual Relations among Models | Ray and chain 5 models |
23. Curvature (1) | Osculating circle, Curvature of pseudosphere (1) |
24. Curvature (2) | What happens if curvature changes? |
25. Gauss-Bonnet Theorem | Curvature of pseudosphere (2) |
26. Touchable Model | (07/06/20) Paper craft of true hyperbolic plane |
27. H(+) Plane and Euclidean Plane | Visual comparison under unchanged length |
28. Analytic Curve | Lambert's quardrangle |
29. Hyperbolic Function | Source, Hyperbolic angle, Definition of logarithm |
30. Inversion and Infinity (under construction) | What is the end of hyperbola? |
31. Upper Half-plane (4) (under construction) | Can we come to Eucledean plane without jump? |
32. Right Angled Polygon | (07/03/29) Infinite polygon |
33. Dodecahedron | 3-D tiling |
34. Ideal Tetrahedron | 3-D tiling |