Euclid's parallel postulate: its nature, validity, and place in geometrical systems .. (1905)
Withers, John William, 1868- · Chicago, Open Court Publishing Co.; [etc., etc.] · leaf 107
quares and by threeregular hexagons, ^ and hence that this space isalways equal to four right angles. In this ancient paving, triangular stones of thesame shape and size were frequently used by placing i*Tylor suggests this as the probable origin of this theo-rem. Anthropology, New York, 1896, p.… … Here the system of equally distant lines is a strik-ing feature. It is also made clear by this figurethat the sum of the interior angles on the same sidemade by the intersection of any two of these equallydistant lines by a third line is two right angles.The obvious fact that this style of paving…
Geometry, Non-Euclidean · Parallels (Geometry)
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