The Divide Edge tool looks like this and is located on the Modify Tab of the Toolbar. Click the Divide Edge button. The 'Edge divisor' counter appears. This specifies the number of edge divisions [n]. Geodesica prompts you to pick a primal edge. The picked edge is divided into n equal lengths. The dual is regenerated automatically. If the Control key is down when clicking an edge, new vertices are flagged as false for primal centroid calculation; this means they are ignored when generating the dual.
The sequence below shows sample use...
1. 'Divide Edge' tool bisects edges 1 to 6
2. 'Make Edge' tool joins new vertices.
3. 'Kill Vertex' tool deletes center vertex
4. Primal and Dual.