Decagon
Videos
In geometry, a decagon is a ten-sided polygon or 10-gon. The total sum of the interior angles of a simple decagon is 1440°.
Timurid Qur'an decagon
Ioanniskepplerih 00kepl 0078
Golden ratio
Videos
In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. Expressed algebraically, for quantities a and b
Michael Maestlin, the first to write a decimal approximation of the ratio
Dan Shechtman demonstrates quasicrystals at the NIST in 1985 using a Zometoy model.
Da Vinci's illustration of a dodecahedron from Pacioli's Divina proportione (1509)
Detail of the saucer plant, Aeonium tabuliforme, showing the multiple spiral arrangement (parastichy)