Thoughts on mathematics education from a new teacher

Geometry Problems

The problems here come from Geometrische Wiederholungs und Denkaufgaben by Paul Eigenmann (Ernst Klett Verlag, Stuttgart, 1964). This book is rather difficult to obtain outside of Germany: the only copy I located near me is at the University of Illinois Urbana-Champaign library. I was introduced to these problems by a paper xerox copy credited to Peter Genta (Carlinville High School, Carlinville, IL, 1988). I started re-creating the problems in GeoGebra and rendering them as PNG. The original notebooks for most of these can be found at the tech page. I will update this gallery as re-create more of these. The numbering in the filenames comes from the original source. (I would re-post scans of the original source, but I am concerned about copyright — at least if I re-create them in GeoGebra, as I understand it, the images are my own to redistribute.)

There are a total of 176 problems. They are put into 4 groups by Eigenmann:

Group 1: Numbers 1-48: Angles in triangles, Symmetry, Areas of triangles and quadrilaterals

Group 2: Numbers 49-96: Circles and Pythagorean Theorem

Group 3: Numbers 97-144: Similarity, Proportionality, Heron’s Formula

Group 4: Numbers 145-176: Application of Algebra & Equations