# C.a.R.

### Compass and Ruler - Construct and Rule

C.a.R. simulates constructions with a pair of compasses and
a ruler on a computer. By **moving** basic points, students can

- experience changes in the construction,
- check the construction for correctness.

Moreover, **tracks** of points or
polar sets of lines can be generated to establish new
conjectures and gain geometrical insights.

With **functions**, **curves** and **expressions**, C.a.R goes far
beyond compass and ruler. With the powerful **macros** very
complicated constructions can be explored. Other geometries,
elliptic or hyperbolic, can be explored too. Graphics can be
**exported** in various formats, and constructions can be
**embedded** in HTML pages.

Constructions are saved in an open XML based format, and the
program itself is **open sourced** under the Gnu Public License.
C.a.R. has been developed by RenÃ© Grothmann from the
Catholic University of
EichstÃ¤tt.

Pascal's Theorem - Demonstrated with C.a.R.