The four sets of 24 dominoes come boxed together and are colour coded for ease of sorting. Set 1 Complementary Angles total 90° - black and purple ; Set 2 Supplementary Angles total 180° - black and green; Set 3 Angles and triangles - 180° - black and blue; Set 4 Angles and quadrilaterals - 360° - black and red. Working through the sets will give practice in angle recognition and calculation