Measuring tools consist of palettes and tools located on toolbars.

Palettes allow you to drag 'n' drop various commands onto the image viewer.
right click and select help will display the help file to that tool




Toolbars allow you to perform commands by choosing a specific button from the toolbar and then clicking various points on the image viewer.
right click may bring up help or a menu (with a help option) or a property page from which the tools help can be selected