Group specification
===================


o Arrows to manipulate translations

Teaching
========
o Panning to animate translations
o Rotating to animate rotations
o Reflecting to animate reflections 
o G to animate G

Tiling
======
o Segments may cross so area detection becomes awkward.
o Manual trace tile with snapping
o Manual sewing of tile edges together

Paint Tools
===========
Line
Filled PolyLine

Logo
====
Define pattern by turtle moves

Transform