Measurement in math is the act of finding the length, width, height etc... of a certain object, different measurement schemes are used for different objects.
Centimetres for small shapes, Square centimetres for area Centimetres cubed for volume.
There are different ways of measuring geometric shapes, depending on the dimentional qualities of them. For example, measuring a line ----- long, you could count how many dashes there are, and call it 5 dashes long, or you could measure it with a ruler.
But for something like:
------- I I I I -------
You would first use the formula for Area to get the inside size, or use the formula for perimeter. A=LW for a square, So Area = Length * Width
Which is 28cm squared
For perimeter in a square, you take each side and add them together. So