C.a.R. is dynamic geometry program. Basically, it simulates compass and
ruler constructions on a computer. But on a computer, much more is
possible.
Ruler and compass constructions can be changed by dragging one of the
basic construction points. The construction follows immediately. The
student can check the correctness of the construction and gain new
insight.
Tracks of points and animated constructions can help to understand
geometric relations. Tracks can be used as new objects to explore.
With the macros of C.a.R. very complicated constructions become
possible. Macros are also a way to organize the geometric thinking.
Hiding construction details and using colors make constructions clearer
to read. In C.a.R. lines and circles can also be reduced to the
relevant points.
Arithmetic computations, numerical solutions, curves and functions go
beyond classical constructions. It is even possible to construct in 3D
using advanced macros.
Other geometries, hyperbolic or elliptic, can be explored.
C.a.R. works on all modern platforms. Constructions and assignments can
be embedded into web pages easily. C.a.R. has been translated in many
languages.
C.a.R. can be used free of charge, and the source is available under the GPL license.
