Yes,triangles are fun and frustrating! I am doing a pinwheel quilt. So many "practice" pinwheels to the leftover pile.
either the points didn't meet or got cut off. Piecing pinwheels next to pinwheels was impossible. My solution - put a plain or flowered block between pinwheels. Leftovers? Using them in potholders and other little projects. You would be surprised at how many people never notice the mistakes. Just quilt on!