This document is the sixth of seven units developed by the Math Network Curriculum Project. Each unit, designed to be a 2-week module, is a teacher's guide which includes detailed directions along with the courseware and software needed. Teacher intervention in the non-computer activities that begin each unit is required, and the consistent use of small-group instruction makes the units usable in a standard classroom if two microcomputers are present. In the Turtle Geometry Unit, students use a computer program called Turtleworks (developed by Bill Finzer), to learn a language for geometry. They use this language to construct drawings on the computer and to store them on the Network. When not making designs on the computer, students use Turtle-Tractors, devices similar to protractors, to make drawings on paper. Besides learning to express geometrical ideas in a computer language, students discover theorems about polygons, learn to command more than one turtle at a time, and become expert at seeing how a complex design is built of smaller parts. The computer program was developed for use on a Commodore PET Computer with at least 16K of RAM using 4.0 BASIC. (MNS)