Instead, the tip of the ruler can be attached to the wall surface, etc., so if you want to use the ruler to 'measure the length and height of an object', the 'real ruler' is more suitable.

In this KS2 Maths article, you'll learn how to measure accurately using a ruler. We also have a KS2 Maths videos, a quiz and lots of examples.

With Measure Tools – AR Ruler, you never have to remember to bring a tape measure again. Your phone becomes a smart, augmented reality (AR) ruler you can pull out anytime, anywhere.

Microsoft is working on a Screen Ruler tool for PowerToys. The utility has various modes and can measure the distance between objects.