Volume II

<p>The present second volume starts with Euclidean geometry and the text gets a more educational and even more elementary flavour. </p><p>Here I start with Thales theorem about the angle in a semicircle and continue with Euclid's related theorems about angles in a circle.<br>The most simple parts of the Euclidean geometry are given in detail as well as the later parts about similarity and finally area in </p><p>Euclidean geometry with the theorem of Pythagoras and trigonometry and the measurement of the circle. </p><p>Too the lens equation from geometrical optics is treated.</p><p><br>In several sections is recalled the strictly modern view of the first volume beginning with Hilbert's axioms from the Foundations of Geometry. </p><p>After some discussion of logic and axioms in general we go on with a short section about incidence geometries in two dimensions.<br>The theorems from neutral geometry which have been proved in the first volume and are needed again are cited.<br>The relation of analytic and synthetic geometry is treated on Hilbert's rigorous account.</p><p> </p>