Challenge: Multiples of Three

Remember Claire's fun challenge:

Here is the challenge I have been dreaming up. End a long time away, maybe
November 30 or Dec 31. I want to experiment with layouts that involve
multiple size blocks. So you have lots of flexibility.

Make blocks (square, rectangle or long strips) any multiple of three, then
add 1/2 inch to the last measurement:3 1/2 x 3 1/2; 9 1/2 x 9 1/2; 12 1/2 x
12/1/2; 6 1/2 x 9 1/2; 6 1/2 x 12 1/2; 3/1/2 x 45 1/2...get the idea? So
long as their finished dimensions are a multiple of three, it should be
possible to make them fit together.

Try for some primary colors in each, but if you can't that is okay too,
i'll try to put it next to something bright. If anyone needs fabric (or just
wants to have a way to end, when the fabric sent is used up) send me a SASE
and I'll send a fat quarter of a dark fabric for you to brighten up.

Let's see how many bright and varied blocks we can send to Claire!