That depends what aspect of the glass of water you want to measure: its height, its volume, its mass, its index of refraction, etc.
Millimetres
Milliliters or fluid ounces would be reasonable metric units to measure the capacity of a drinking glass. These units are commonly used for measuring liquid volumes and would provide a clear indication of the glass's capacity.
I wiil use water
Glass of water
That depends what aspect of the glass of water you want to measure: its height, its volume, its mass, its index of refraction, etc.
its liters
Pints
Units such as liters, gallons, or cubic feet could be used to measure the volume of water in a full bathtub. Units like meters or kilograms are not typically used to measure volume and would not be suitable for this purpose.
You can use a measuring cup or a graduated cylinder to measure the volume of a glass. Simply fill up the glass with water and then pour it into the measuring cup or graduated cylinder to determine the volume.
What measurements units would be best to measure the amount of wanter in and eye dropper
What measure of units would you use to measure the thickness of a phone book
Gallons (standard) or liters (metric).