Constructions on the Poincaré-disk
摘要
This paper concerns with implementations of constructions inthe Poincaré model of hyperbolic geometry and their applications to proofs ofselected theorems. The main motivation is how some hyperbolic geometric statements can be proven using elementary methods within the model. By embeddinghyperbolic geometry into the Euclidean plane, certain proofs can become moreaccessible and comprehensible.
In this paper, we present two elementary constructions developed by usingthe Poincaré model, followed by novel-approached answers to the following questions. Does a common perpendicular always exist for two ultraparallel lines? Cana given line segment be divided into
Although there exist known answers to these questions, the usual proofs involve strong theorems or trigonometric functions requiring extensive calculations(e.g. [6] and [2]). Instead, hereby we present proofs using elementary tools witheasily understandable steps.