Angle ∠BAC might refer to any of four angles: the clockwise angle from B to C, the anticlockwise angle from B to C, the clockwise angle from C to B, or the anticlockwise angle from C to B, where the direction in which the angle is measured determines its sign (see Positive and negative angles). However, in many geometrical situations it is obvious from context that the positive angle less than or equal to 180 degrees is meant, and no ambiguity arises. Otherwise, a convention may be adopted so that ∠BAC always refers to the anticlockwise (positive) angle from B to
Postmodern mathematics discussions of the philosophy of mathematics and mathematics education and has extensive articles on postmodern mathematics. He introduced the idea of 'fuzzy logic'. This idea rejects the Aristotelian Law of Truth and fallibility of an object (the notion that an object is either true or false). He instead proposed the existence of 'degrees of truth', the idea that an object is characterised into various degrees of truth. Thomas Kuhn (1922-1996) introduced the idea of paradigm shifts in sciences. he asserted that the paradigms and theories in sciences are not fixed but are instead on a continuum and hence are subject