Depends on the currency that you are referring to.
a 30cm ruler
To measure 720mm with a 30cm ruler, first note that 720mm equals 72cm. Since the ruler only measures up to 30cm, you would need to use it multiple times. Measure 30cm twice to get 60cm, then measure an additional 12cm using the ruler, which can be achieved by marking the 12cm point on the ruler after measuring the full 30cm twice. This will give you a total of 72cm or 720mm.
20g
A typical 30cm plastic ruler weighs around 30-40 grams, while a wooden ruler of the same size may weigh slightly more.
30cm is about 12 inches or 1 foot in length
To measure a 750mm long ribbon using a 30cm ruler, first convert 750mm to centimeters, which is 75cm. Lay the ruler down alongside the ribbon and mark the end of the 30cm measurement. Move the ruler to the end of the marked point and measure another 30cm, marking again. Finally, measure the remaining 15cm to reach a total length of 75cm (or 750mm).
Look at a ruler, if you don't know....
Yes.
A 30cm Ruler.
Anything that measures length: a 30cm ruler, a metre ruler, a tape measure etc.
Depending on the size of it id say either a 15cm ruler or a 30cm ruler.
Depending on the size of it id say either a 15cm ruler or a 30cm ruler.