I would use a ruler (metric) but careful to only measure the inside. You could also wet the beaker and place it on a piece of paper (rim down). This will leave a wet ring that you can measure. But be sure only to measure the dry inner part of the ring.
Beaker's are typically graduated in mililiters, and a mililiter is a cubic centimeter. So while centimeters would seem a reasonable choice, I would instead suggest using milimeters as they are well suited for precise measurements. There are 1000 cubic milimeters in one ml anyways so the conversion is easy if you were trying to measure the beaker in mm, calculate the volume, and convert to ml.
liquid volume
For this you would have to look at the beaker. Most modern beakers measure in litres and millilitres.
The diameter is the measurement of a line that goes right through a circle, through the centre point. In cases where we have a ring or some other such object with multiple circles, we would have an external diameter and an internal diameter. The internal diameter is the diameter of the inner circle. The external diameter is the diameter of the outer circle.
You should clarify what you want to measure about it: its diameter, mass, weight, color, etc. If you want to measure its diameter, that would usually be specified in microns (= micrometers).
The major diameter is the diameter of the crest of the thread. Use a Vernier gage and mesure the diameter of the crest points of contact ( maximum external thread diameter). Unified National thread series defines the expected major diamter and tolerance. For internal threads ( nuts) the major diameter is the diameter of the roots of the thread.
A beaker filled with liquid can be used to measure the volume of a non-soluble solid, or of a liquid. If the mass of the solid or liquid sample has been previously determined, the liquid (usually water) displaced from a filled beaker will provide the volume of the sample. Mass divided by volume gives the density. One of the early uses of the process was to identify counterfeit gold coins. In order to weigh the same as real gold coins, fakes would have to be thicker, and therefore have greater volume.
First of all it's "What unit of measurement would you use to measure the diameter of a drink can?" Secondly you would probably use either centimeters or inches, depending on where you are in the world.
you would use a scale to measure the mass and a beaker to measure the volume. i need another tool
beaker
a large beaker and sponge
Calipers are used to measure the dimension of anarticle. In measuring a section of pipe you would use an inside caliper to give the internal diameter, and an outside caliper to give the external diameter. The difference being the thickness of the pipe wall.