- Quadrilateral (Wikipedia)
In geometry a quadrilateral is a four-sided polygon, having four edges (sides) and four corners (vertices). The word is derived from the Latin words quadri, a variant of four, and latus, meaning “side”. It is also called a tetragon, derived from greek “tetra” meaning “four” and “gon” meaning “corner” or “angle”, in analogy to other polygons (e.g. pentagon). Since “gon” means “angle”, it is analogously called a quadrangle, or 4-angle. A quadrilateral with vertices A, B, C and D is sometimes denoted as ABCD.
- Satan (Wikipedia)
Satan, also known as the Devil, is an entity in Abrahamic religions that seduces humans into sin or falsehood. In Judaism, Satan is seen as an agent subservient to God, typically regarded as a metaphor for the yetzer hara, or “evil inclination”. In Christianity and Islam, he is usually seen as a fallen angel or jinn who has rebelled against God, who nevertheless allows him temporary power over the fallen world and a host of demons. In the Quran, Shaitan, also known as Iblis, is an entity made of fire who was cast out of Heaven because he refused to bow before the newly created Adam and incites humans to sin by infecting their minds with waswās (“evil suggestions”).