Rhombiominoes has 20 tiles, divided 7-7-6 among 3 colors, with the colors assigned to tiles so that a solution is possible with no two of the same color sharing sides. Puzzle solver extraordinaire George Sicherman has proposed making symmetrical shapes with just the pieces of any one of the colors. He solved several beautiful shapes for each of the colors and reports that they were difficult to find. They have mostly diagonal symmetry and a few rotational ones. Can you find others?
Puzzle enthusiast and designer Dan Klarskov in Denmark came up with these handsome zigzag solutions for the full Rhombiominoes set, with two-fold rotational symmetries: