Some time ago (not in this century) I took plane geometry, not directly from Euclid. My teacher was Miss Helland, a wonderful teacher who also taught me solid geometry, and had the courage to take … ...

THIS book contains a revised edition of Books III., IV., V., of the “Syllabus of Plane Geometry” drawn up by the Association for the Improvement of Geometrical Teaching, with demonstrations of ...

Howard F. Munch, Some Methods of Teaching Plane Geometry, The High School Journal, Vol. 12, No. 1 (Jan., 1929), pp. 5-16 ...

If we accept it, we get Euclidean geometry, but if we abandon it, other geometries become possible, most famously the hyperbolic variety. Here’s how the parallel postulate works.

THIS is one more Text-book of Geometry. It adopts completely the general principles of the geometrical reformers in England, in the classification of the rems according to their subjects, the free ...