Use the Parallel or Perpendicular Lock When Measuring
Click Review tab > Measure panel > Measure drop-down.
Click the Area Measure tool.
Click the Review tab > Measure panel > Lock
drop-down, and choose from:- Parallel
. - Perpendicular

- Parallel
In the Scene View, hover your mouse on the model and use the surface snap
to select a surface. Your measurement will be parallel or perpendicular to this surface.Click the start point of the distance to be measured in the Scene View.
The measure line is displayed as a solid magenta line when it is parallel to the surface of your start point:

or as a solid yellow line when it is perpendicular to the surface of your start point:

Click the end point of the distance to be measured in the Scene View.
The optional dimension label displays the measured distance.
Command entry: Press L (parallel) or P (perpendicular) when using a Measure tool.