Measuring procedure
To measure the length of a segment, click the first point that defines the distance you want to measure, move your mouse to the endpoint and click on it.
If you wish to measure curved lines, click first then right-click on the point where the curve starts; from the shortcut menu that appears, select the ‘Drawing arc’ option, which can be enabled or disabled during a measurement. Alternatively, you can use the F10 key.
Measuring Discontinuous Segments
Undoing a measurement (Ctrl+Z)