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A turn is a unit of plane angle measurement equal to 2 radians, 360° or 400 gon. A turn is also referred to as a revolution or complete rotation or full circle or cycle or rev or rot. A turn can be subdivided in many different ways: into half turns, quarter turns, centiturns, milliturns, binary angles, points etc. ==Subdivision of turns== A turn can be divided in 100 centiturns or milliturns, with each milliturn corresponding to an angle of 0.36°, which can also be written as 21′ 36″. A protractor divided in centiturns is normally called a percentage protractor. Binary fractions of a turn are also used. Sailors have traditionally divided a turn into 32 compass points. The ''binary degree'', also known as the ''binary radian'' (or ''brad''), is turn.〔(【引用サイトリンク】 title=ooPIC Programmer's Guide )〕 The binary degree is used in computing so that an angle can be represented to the maximum possible precision in a single byte. Other measures of angle used in computing may be based on dividing one whole turn into 2''n'' equal parts for other values of ''n''. The notion of turn is commonly used for planar rotations. Two special rotations have acquired appellations of their own: a rotation through 180° is commonly referred to as a half-turn ( radians),〔(【引用サイトリンク】 title=Half Turn, Reflection in Point )〕 a rotation through 90° is referred to as a quarter-turn. A half-turn is sometimes referred to as a reflection in a point since these are identical for transformations in two-dimensions. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Turn (geometry)」の詳細全文を読む スポンサード リンク
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