http://www.pubquizhelp.com/sci/polygon.html
No. ofsides Polygon Name Internal Angle
3 Triangle 60°
4 Square or Quadrilateral 90°
5 Pentagon 108°
6 Hexagon 120°
7 Heptagon 128.571°
8 Octagon 135°
9 Nonagon or Ennagon 140°
10 Decagon 144°
11 Hendecagon or Undecagon 147.273°
12 Dodecagon 150°
13 Triskaidecagon 152.308°
14 Tetrakaidecagon 154.286°
15 Pendedecagon 156°
16 Hexdecagon 157.5°
17 Heptdecagon 158.824°
18 Octdecagon 160°
19 Enneadecagon 161.053°
20 Icosagon 162°
30 Triacontagon 168°
40 Tetracontagon 171°
50 Pentacontagon 172.8°
60 Hexacontagon 174°
70 Heptacontagon 174.857°
80 Octacontagon 175.5°
90 Enneacontagon 176°
100 Hectagon 176.4°
1000 Chiliagon 179.640°
10000 Myriagon 179.964°
100000 Megagon 179.996°
10100 Googolgon almost 180°