Nonagon

Nonagon – a polygon with 9 sides

NoNagon
NiNe of them

Nine of them sounds like nonagon so makes this easy to remember.

If none are gone (nonagon) then a cat has nine lives. 

Example 1

A regular nonagon has nine sides of equal length.

Example 2

If you add up all the internal angles of a regular convex nonagon you will get 1260°.

Example 3

A regular convex nonagon has an internal angle of 140° between each side.

Example 4

This shape looks like a Y but as it has 9 sides, it’s a nonagon.

Example 5

Irregular nonagons such as this one may not have a symmetrical shape but will still have nine sides.