9.5 cm x 8.6 cm x 0.6 cm / 3.7 in x 3.4 in x 0.25 in
Please note that plastic colors vary.
Two squares form a rectangle. Two triangles (one half of the square each) are attached to the squares but only to the longer side(s) of the rectangle. 9 pieces represent a full set. You need 2 more squares and 2 more triangles to fill the 5x6 tray completely. Those 2 squares are placed in two diagonal corners, so ther are two empty triangles - somewhere....