Selection prerequisites: Any number of objects including two points
This Transform menu command marks for future translations the vector determined by the two most recently selected points. The first of these two points is the initial point of the vector, and the second is the terminal point of the vector.
When you choose this command, you will see a brief animation from the initial to the terminal point confirming that the vector has been marked.
After marking a vector, future translations for which you specify the Translation Vector: Marked option will be based on this vector. Such translations will translate objects by a distance equal to the distance from the initial to the terminal point and in the same direction as the direction from the initial to the terminal point.
For instance, if you mark the vector from A to B as in the figure, and then translate CDE, the result will be a second triangle translated by the distance from A to B and in the direction from A to B. As you adjust the vector by dragging A or B, the translated image of CDE adjusts accordingly.
You can also mark a vector after choosing Translate. With the Translate dialog box open, click two points in your sketch to designate the initial and terminal points of the desired vector.