measurements across slices

Operating system: win 10
Slicer version: 4.8
Expected behavior:
Actual behavior:

slicer newbie. How do I measure distances across slices on skull ct’s. Once the measurement is done how do I erase the fiducials or ruler landmarks for another measurement?
thank you

.

You can either place annotation rulers; or place markup fiducial points and see distance by right-clicking in the point list in Markups module.

Probably the simplest way to delete annotations and markups is to go to Data module, right-click on what you want to remove, and choose Delete.