- In geometry, an equilateral triangle is a triangle in which all three sides have the same length. In the familiar Euclidean geometry, an equilateral triangle is also equiangular; that is, all three internal angles are also congruent to each other and are each 60°. It is also a regular polygon, so it is also referred to as a regular triangle.
- 2001: A Space Odyssey (allthetropes.org)
2001: A Space Odyssey is a 1968 science-fiction film, written and directed by Stanley Kubrick, with help from Arthur C. Clarke (who also wrote a novel version in tandem with the film’s production), and inspired in part by Clarke’s short story “The Sentinel”.