Euclid's Big Problem - Numberphile
26:36
Epic Circles - Numberphile
15:28
The Beautiful Story of Non-Euclidean Geometry
18:55
The Feigenbaum Constant (4.669) - Numberphile
8:32
Portals to Non-Euclidean Geometries
16:53
The problem Euclid couldn't solve
15:39
An amazing thing about 276 - Numberphile
38:28
A Miraculous Proof (Ptolemy's Theorem) - Numberphile
10:54