## Geometry: Common Core (15th Edition)

To find the coordinate of the midpoint, first find the length of $\overline{AG}$. AG=$|-3-3|=|-6|=6$ Since AG=6, the midpoint is half way between, or 3 units from, each endpoint. One endpoint is -3, so: Midpoint=$-3+3=0$ The coordinate of D is 0, so D is the midpoint.