British flag theorem that and by a similar argument the squared lengths of the distances from "P" to the other three corners can be calculated as Therefore: This theorem takes its name from the fact that, when the line segments from "P" to the corners of the rectangle are drawn, together with the perpendicular lines used in the proof, the completed figure somewhat resembles a Union Flag. British flag theorem In Euclidean geometry, the British flag theorem says that if a point "P" is chosen inside rectangle "ABCD" then the sum of the squared Euclidean distances from "P" to two opposite corners of
The Witch's Familiar The Witch's Familiar "The Witch's Familiar" is the second episode of the ninth series of the British science fiction television series "Doctor Who". It was first broadcast on BBC One on 26 September 2015. It is written by Steven Moffat and directed by Hettie MacDonald. It is the second part of the story, following "The Magician's Apprentice". In the pair of episodes, alien time traveller the Doctor (Peter Capaldi) battles his old enemies the Daleks and attempts to save his companion Clara Oswald (Jenna Coleman). Julian Bleach and Michelle Gomez reprised their roles as Davros and Missy, the current incarnation