By magic, my previous posting evaporated !
1. irregular, regular [various constructions]
2. star 5/2 maths
3. Holly star

Maths Polygon Area_Perimeter.sm (33 КиБ) скачан 95 раз(а).
Maths Polygon Star 5_2.sm (965 КиБ) скачан 83 раз(а).