Inscribed angle its intersection points equals half of the central angle subtended by the chord. See also Tangent lines to circles. The inscribed angle theorem is used in many proofs of elementary Euclidean geometry of the plane. A special case of the theorem is Thales' theorem, which states that the angle subtended by a diameter is always 90°, i.e., a right angle. As a consequence of the theorem, opposite angles of cyclic quadrilaterals sum to 180°; conversely, any quadrilateral for which this is true can be inscribed in a circle. As another example, the inscribed angle theorem is the basis for several
How Many More Times Wolf's "How Many More Years" (1951), as well as other songs by blues musicians he admired at the time of recording. In 1970, "How Many More Times" was dropped from Led Zeppelin's typical setlist, although they continued to perform it on occasion until the early stages of their 1975 North American tour, when it was re-introduced in full as a result of Jimmy Page's injured finger, which temporarily prevented him from playing the more challenging "Dazed and Confused". In a contemporary review for "Led Zeppelin" on release, John Mendelsohn of "Rolling Stone" called "How Many More Times" as the album's