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3. A regular pentagon Polygons The word polygon has its roots in the Greek language and means many-angled. A regular polygon is a polygon with all sides equal and all angles equal.

4. Some regular polygons

5. Regular Equilateral Triangle Square Pentagon Hexagon Septagon/Heptagon Octagon Nonagon Decagon Hendecagon Dodecagon Hexadecagon Icosagon 3 4 5 6 7 8 9 10 11 12 16 20

6. Calendar Septagon Octagon Nonagon Decagon 7 8 9 10 What is link between the calendar and the names of the polygons below? June6 th May5 th April4 th March3 rd February2 nd January1 st December12 th November11 th October10 th September9 th August8 th July7 th

7. Septagon Octagon Nonagon Decagon 7 8 9 10 What is link between the calendar and the names of the polygons below. June6 th May5 th April4 th March3 rd February2 nd January1 st December12 th November11 th October10 th September9 th August8 th July7 th

8. Septagon Octagon Nonagon Decagon 7 8 9 10 What is link between the calendar and the names of the polygons below. Junius4 th Maius3 rd Aprilis2 nd Martis1 st December10 th November9 th October8 th September7 th Sextilis6 th Quintilis5 th Legend has it that the mythical first king of Rome, (Romulus), created a 10 month year of 304 days when he founded the city in 735 BC. March was the first month, named after Martis the god of war. Aprilis may refer to raising hogs. He named Maius after a local Italian goddess and Junius after the queen of the Latin gods. After that he named them by their number, using Latin prefixes. The Calendar (David Ewing Duncan) Januarius Februarius Romulus’s 304 day calendar was unworkable for an agricultural people who needed a reasonably accurate calendar to guide them through the seasons. It was Romulus’s successor, King Numa,who added 2 more months to the calendar in about 700 BC – Januarius and Februarius. Eventually under Julius Caesar, these became the first 2 months of the year.

9. Septagon Octagon Nonagon Decagon 7 8 9 10 What is link between the calendar and the names of the polygons below. Junius6 th Maius5 th Aprilis4 th Martis3 rd 2 nd 1 st December12 th November11 th October10 th September9 th Sextilis8 th Quintilis7 th Over time the Romans improved the calendar still further and in tribute to the improvements made by Julius Caesar (365 day calendar), the Senate changed Quintilis to Julius. Later still, Sextilis was renamed Augustus in honour of the great Emperor. Januarius Februarius Julius7 th Augustus8 th

10. An irregular polygon is a polygon whose sides and angles are not all equal. An irregular pentagon

11. Some irregular polygons

12. 3 4 5 6 7 8 Triangle Quadrilateral Pentagon Hexagon Septagon/Heptagon Octagon Irregular

13. Polygon Arch 1 Quadrilateral Triangle Pentagon Hexagon Quadrilateral Pentagon Heptagon

14. Polygon Arch 2 Triangle Quadrilateral Hexagon Pentagon Triangle Heptagon

15. Polygon Arch 3 Pentagon Quadrilateral Hexagon Heptagon Pentagon Triangle Pentagon Nonagon

16. What’s happened? (mathematically speaking) A hendecagon is laying eggsagons! Thanks E.G (mathematical pie) And finally: