You can find the source of a dimension by pre-selecting (use Shift Key) the dimension witness line and ArchiCAD will highlight what was originally selected to create the dimension. In this example the window was the source of the pre-selected witness line.
You cannot place an Arc Length dimension using Geometry Method “Arc Length” with the static dimension box checked, uncheck this box and you can then place your dimension.
By varying the arrow head and style of dimensions you can use dimensions as double ended and stylized labels, useful for labeling framing and areas.
If you have changed the dimension string’s text position or orientation (e.g. Drag, Rotate). You can undo these changes globally (i.e. in the entire project), by opening the Options > Project Preferences > Dimensions dialog box, and ticking the Revert All Dimension Text to Automatic Position checkbox. Note : This action is not undoable. Alternatively
To join or combine two separate dimension strings / chains select the main string and Ctrl click (PC) or Command click (mac) on the string that you want to add.