The Animate tool allows you to see the effect that changing a dimension through a range of values would have on the sketch. You can set a minimum and maximum scale in the Options dialog box to apply to the dimension. The system will run through several cycles (set in toolbox edit box) of modifying the selected dimension between its value times the minimum factor and its value times the maximum factor. The right mouse button speed selections determine how many intermediate steps are calculated and displayed, thus effecting the speed of the animation. The speed will also be effected by the complexity of the sketches in the current plane. The sketch will return to its original state when finished.