- In geometry, a nonagon (/ˈnɒnəɡɒn/) or enneagon (/ˈɛniəɡɒn/) is a nine-sided polygon or 9-gon.
- Djibouti (Wikipedia)
Djibouti, officially the Republic of Djibouti, is a country in the Horn of Africa, bordered by Somalia to the south, Ethiopia to the southwest, Eritrea in the north, and the Red Sea and the Gulf of Aden to the east. The country has an area of 23,200 km2 (8,958 sq mi).
- Decagon (Wikipedia)
In geometry, a decagon (from the Greek δέκα déka and γωνία gonía, “ten angles”) is a ten-sided polygon or 10-gon. The total sum of the interior angles of a simple decagon is 1440°.
- Octagon (Wikipedia)
In geometry, an octagon (from the Greek ὀκτάγωνον oktágōnon, “eight angles”) is an eight-sided polygon or 8-gon.
