To be honest, I don't know what you can use this square for....
I guess is can be an alternative to a spaced or it can be used for designs of a sky scraper. I dunno.
Step 1: Making the Square ( 1 )
Just slide in the connecting part of the black pieces into each other.
You'll need 2 of these half squares.
Step 2: Finishing the Square.
Slide the 2 parts in to each other.
Step 3: Your Done...
Here is your useless black knex square!