Seastar-
I know you are interested in teaching your child to play with Tangrams and I thought you might enjoy this wooden MelissaandDoug 'Pattern Block' set we have...It comes with multiple wooden two-sided boards to copy, and I am including the site that I found where you can download additional pattern blocks for free...
http://prekinders.com/pattern-blocks/We also use the shapes that are included...hexagon, rhombus, triangle, square, rectangle sort of thing for patterns and sorting activities...
One thing, the pieces are smaller than I expected so this is one of those activities that are kept up high and brought out with Mommy...which I have found only adds to the Allure