- Square (Wikipedia)
In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90-degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length adjacent sides. It is the only regular polygon whose internal angle, central angle, and external angle are all equal (90°), and whose diagonals are all equal in length. A square with vertices ABCD would be denoted ◻ ABCD.
- Alnitak (stars.astro.illinois.edu)
ALNITAK (Zeta Orionis). With brilliant Betelgeuse and Rigel dominating great Orion, we pay little heed to the individual stars of the Hunter’s belt except as a group, the trio the Arabs called the “string of pearls.” All second magnitude, Johannes Bayer seems to have named the stars Delta, Epsilon, and Zeta from right to left.
- Alnitak (Wikipedia)
Alnitak is a triple star system in the constellation of Orion. It has the designations ζ Orionis, which is Latinised to Zeta Orionis and abbreviated Zeta Ori or ζ Ori, and 50 Orionis, abbreviated 50 Ori. The system is located at a distance of several hundred parsecs from the Sun and is one of the three main stars of Orion’s Belt along with Alnilam and Mintaka.
