A ruler, tape measure, yardstick are three examples. Laser measuring devices are also becoming popular.
a ruler
If you want to measure the length, use a ruler.
A tape measure.
depends on what item you are measuring
ruler
A ruler or tape measure.
Meters (about 3 feet)
hygrometer
Well, I would use a tape measure! If you needed something a little more accurate, you could use laser measuring devices.
ruler, yardstick, or meterstickA ruler or measuring tape ... mind you you can use anything as a tool to measure .... so long as you know the length of the tool you are using ...
SI UNIT Usually, at a normal classroom size, the tool to use would probably be to measure it in either yards or meters. TOOL A yard stick
You take it and roll it out and use a length measuring tool to measure it's approximate length in yards feet inches centimeters etc... :)