model_size 20 x 17,5 x 20
model_weight 350
model_catalognum 150/ 38
model_objectnum 97620-000
model_originalprize 78 DM
model_since 1958.
model_externallinks Description in the catalogImage in the catalog
model_from :
nav_classification
The circle as orthogonal projection of an ellipse
An ellipse, that can rotate about its minor axis, may be fixed by means of two supporting triangles in such a position, where its orthogonal projection is a circle. In the model the affin correspondence between an ellipse and its minor auxiliary circle is to be seen.