How to measure a 2d distance or draw a flat line at a specific elevation

This video covers 2 system variables in AutoCAD, OSNAPZ and ELEV. You can use both of these variables to: (1) Measure the 2d distance between two points (https://surveyorinsider.com/measure-2d-distance-autocad/) (2) Draw a line or trace existing objects but the line you draw is flat (https://surveyorinsider.com/draw-flat-line-autocad/) Watch the whole video to learn more about these two system variables.