(default keyboard shortcut Ctrl E)
You will often need to estimate distances in the modeling process. The grid size can yield reasonably accurate figures, but if the two points are not aligned somewhat vertically or horizontally, estimating can be more difficult.
Fortunately, Modeler provides what is best described as a virtual tape measure. With it, you can measure the distance between any two points in any view.
To use the Measure Tool:
Choose Detail > Measure > Measure > Measure Tool and then drag between the two positions you want to measure. The information display in the bottom left corner will indicate the exact distance.
You can reposition either end by dragging it. To reset, click in a non-active part of the interface.