If a square has an area of 2 cm squared, what is its length?

I am sorry, I misread the question.  I thought it said the breadth was 2cm find the length.   

Anon you are correct the side length is   $$\sqrt2$$  cm  

This number might look weird but it is NOT imaginary.

It is an IRRATIONAL NUMBER that means it cannot be written exactly as a decimal or as a fraction.

So if you want to write it with digitr it will always be an approximation.

$${\sqrt{{\mathtt{2}}}} = {\mathtt{1.414\: \!213\: \!562\: \!373\: \!095}}$$ cm        This is an approximation of the side length :)

It is a square.

What properties to squares have?

Draw one!

You can answer this yourself :))

A square can't have a area of 2 square cm BLOB

It is the imaginary number which is the square root of 2