# Ruler & compass --- Introduction ---

Geometric construction by ruler and compass is a fascinating mathematical problem since ancient times. If on the theoretical side, today one knows exactly what are the constructions which are possible by ruler and compass, on the practical side, it is always interesting to know how to construct which or which configuration concretely.

This application allows you to simulate ruler and compass constructions on the net, either freehand, or for predified goals going from basic operations to sophisticated ones such as the regular polygon of 17 sides. In most of the cases, there is a solution which you can follow step by step, and/or a hint which explains the idea.

A few dozens of predefined goals are distributed into the following levels.

• Level 0 : free construction, with no starting object nor predefined goal.
• Level 1 : basic constructions.
• Level 2 : easy constructions.
• Level 3 : various constructions.
• Level 4 : interesting constructions.
• Level 5 : impossible constructions.
If you have saved a script of construction sequence, you can load it by here to repeat the sequence.