Highlight the part to be measured, select the measurement tool, single left click on the start point and drag your cursor to the measurement point (do not click) just let the blu dot hover over that point and look at the dialogue box. This allows you to take multiple measurements from any single point.
Gene,
Nest your cabinet and it will show you the part size less the edge banding and will show you the dado depth and width which will show you the clearances.
Kerry