1-1-3-3 April 1, 2014Tessellation Nation3-shape tessellationRaymond K. Houston 1-1-3-3 Share this:EmailPrintFacebookMorePinterestTwitter Related posts: 1-1-4-4 1-1-3M-3M 1-1-4M-4M 1-2-1-2 1-3-1-3 1-1M-1-1M 1-4M-1-4M 1-3-3-1 1-1M-1M-1 1-2M-2M-1