If you wish to find the distance between any two points on the display, use the "Measure" tool from the tool bar.
Figure 4.4

This mode can also be invoked with the Toggle Measure Distance command (in menu Edit / Modes / Edit). Another way to measure distances is to use the cursor coordinates, displayed in the status area.

In measure mode, each click places a new point on the display, and shows the distance to the previous point. Clicking the right button lets you start a new measure point without connecting it to the previous one. Double-clicking the right button removes the measurements.

The measured distance can be used by the Array... command (in menu Edit) to specify spacing (see Section 6-4).