I saw this idea being used on The Homeschool Den, and the printables come from PreKinders. Faith has never been very interested in the pattern blocks but she took a liking to the patterns for animals that I printed out.
Here Eve is combining shapes to build triangles. Faith later worked on this one and found lots of very inventive ways to combine the shapes and it was a learning curve for her. Whereas Eve intuitively knew which shapes would fit, Faith adopted trial and error to find out.
We learned some shape vocabulary along the way..... trapezium and parallelogram (or palallemogram of you are Faith!) were the new ones for the girls.