Special right triangle triangles are used to aid in calculating common trigonometric functions, as below: The 45°–45°–90° triangle, the 30°–60°–90° triangle, and the equilateral/equiangular (60°–60°–60°) triangle are the three Möbius triangles in the plane, meaning that they tessellate the plane via reflections in their sides; see Triangle group. In plane geometry, constructing the diagonal of a square results in a triangle whose three angles are in the ratio 1 : 1 : 2, adding up to 180° or radians. Hence, the angles respectively measure 45° (), 45° (), and 90° (). The sides in this triangle are in the ratio 1 : 1
The Three Degrees Live England. This credit has been corrected on the digital re-issue. The Three Degrees Live The Three Degrees Live is a 1976 live album by Philadelphia-based female vocal trio The Three Degrees who scored major international success with 'When Will I See You Again?'. The album charted at #34 in the US R&B Album chart and at #199 in the Billboard Top 200. During a UK tour in 1975, The Three Degrees performed at Bailey's in Leicester, England, and the evening's concert was recorded and subsequently released by Philadelphia International Records as "The Three Degrees Live". The setlist for the concert