Justus brought in a book Can You Solve These? with lots of tricky maths questions. Here's one:
We used an online tool to try it out. (link) We made this:
We think it will carry on forever.
We also think that there are twice as many triangles as squares.
That's strange! An infinite number of squares, but twice as many triangles.
Can you... click on the link, and continue the pattern?