You measure one linear dimension - usually the longest, but the orientation may lead t another.
a ruler is used to measure it and cm, sometimes inches to
By length width and height
It is necessary because measuring tools help you measure the length of an object accurately.
It is easiest to measure the length, breadth and height and multiply them together.
A meter rule.
You don't measure with length. You measure the length of an object with a ruler. You would use inches or metres as your units.
Use a ruler.
a cm
a ruler
You use a ruler or tape measure to measure this in units of choice
a ruler is used to measure it and cm, sometimes inches to
No. Grams are for weight.
By length width and height
The linear length of an object can be measured in centimetres.
It is necessary because measuring tools help you measure the length of an object accurately.
The length of any object you need to measure within the centimeter reasonable accuracy.
If you want to measure the length, use a ruler.