In this session, we will be presenting examples of the use of GeoGebra in our graduate-level, completely online program for high-school mathematics teachers. We will be focusing on examples of uses of Geogebra by the mathematics teachers as 1) a master; 2) a servant; 3) a partner; and, 4) an extension of self in the classroom. The materials developed by teachers with respect to a specific geometric task will be shared with session participants.