C.a.R. (Compass and Ruler) is dynamic geometry program, which simulates the computer in the construction of figures using a ruler and a compass. The application is free, and the source code is available under the License GPL.

In addition to its main function, C.a.R. (Compass and Ruler) offers many interesting possibilities, to facilitate learning processes quickly and visualize all sorts of shapes and geometric objects: points, lines, segments, circles, arcs, angles, polygons and conic sections.

You can modify the constructions carried out, with only change the position of basis points, dragging with the mouse. The new image is generated instantly. Thus, the user can analyze the effects of the changes and verify if the construction is correct.

With C.a.R. (Compass and Ruler) can be used mathematical expressions, including comprehensive functions and differential zeros. The formulas are displayed with Greek letters, and the texts are replaced by expressions corresponding value.

The animated images and the possibility of revising the basic points of the figures, converted a career (Compass and Ruler) in an extremely useful tool for understanding the geometric relationships.

Thanks to its templates (macros) predefined, with Compass and Ruler is easy to run even more complicated constructions, and organize thinking geometric. With more advanced macros is even possible to generate bodies in three dimensions. To see more clearly the figures, simply to hide the details and use different colors.

C.a.R. (Compass and Ruler) shows the construction process step by step, or in a movie. Its simple interface, along with contextual help make it fun and a useful tool to better understand the geometric elements more complex.