Two kinds of extensions to David Lewin's transformation theory are proposed. First, cross-type transformations transform one sort of object to another: for instance, mappings from triads to seventh ...

Materials were written for an entire year's course in geometry in which transformations were used to develop the concepts of congruence, similarity, and symmetry, as well as being a vehicle for proof.

Discusses the properties and types of triangles, explaining that a triangle is a closed figure with three sides and angles. It categorizes triangles into equilateral, isosceles, scalene, obtuse, right ...