geometry question

[Kiến Vàng]

I donot know how to call a 7 or a 9 sided/angles figures.

I know
triangle = 3 sided/angles
quadangle, tetragon
pentagon
hexagon
? = 7 sided/angles
octagon
? = 9 sided/angles
decagon

polygon, isogon = many sided/angles figure

Thanks for all yours help!

KV
:)

[Trung Quốc]

tetra
penta
hexa
hepta
octa
nina

[Kiến Vàng]

Thanks QT

[Kiến Vàng]

heptagon is ok
no word in the dictionary for ninagon

[Tuong-Vi]

9 nonagon
10 decagon
11 undecagon
12 dodecagon etc

[Tammy Nguyen]

hihi,
These I know, not from studying math, but from studying Latin roots. :D

poly =many
iso= parrallel, equal, as in isoceles triangle with 2 equal side, isometric, isobars, etc....
100-- centi
1000-- milli

[Kiến Vàng]

Thank you everyone !

[Tuong-Vi]

chị tammy ơi, hình như theo tuongvi biết là
10 or 10^1 = deca
100 or 10^2 = hecto
1000 or 10^3= kilo
1000000 or 10^6 = mega

còn centi = 0.1 or 10^-1
milli = 0.001 or 10^-3
micro = 0.000001 or 10^-6