the best way to measure mass is using grams
The best way to measure a highway is in miles.
mass
mass
A balance is the best tool for measuring mass.
The same way you measure other everyday objects. One way to do this is by weighing them. This is an indirect measurement, but on Earth, you can consider weight to be proportional to mass.
mass is best measured by fluid volume displacement
the best way to measure body fat is using a Body Mass Index (BMI). It provides a lot more information than a bathroom scale. This calculation uses a ratio of weight to height to estimate body fat.
Do to its size, the mass of a peanut would probably best be measured in grams.
grams
Meters
Not by any sensible, repeatable way, no.
the way to measure those by with times height time length.