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.

The pupillary distance (PD) measurement is a requirement for people who want to purchase eyeglasses. Here, find out how to measure your PD using a mirror and a ruler.

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.

Considering this, it doesn't surprise us that she would start using a ruler to measure and guide her contour application.