Duadesgon

Duadesgon or 20gon is figura har 20 gono ji 20 comen.

Meter

Moyun gono de pinpan duadesgon hare 162° ji oto maxuscu cel 3240°.

Peryaje

Peryaje de pinpan duadesgon har comenli lungoje a:

${\text{Peryaje}}=5a^{2}(1+{\sqrt {5}}+{\sqrt {5+2{\sqrt {5}}}}).$

Misal

• 

  Duadesgonli kostruixey in Usa (kostruido fe 1903)