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 Kenny Gamble and Leon Huff, where they had their greatest successes. The first song they recorded for the label was with the studio band MFSB, titled "TSOP (The Sound of Philadelphia)", which was the theme song for "Soul Train". In October 1973, the group also made an appearance on the American television sitcom "Sanford and Son" (season 3, episode 4), singing their song "I Didn't Know". Their first album for the Philadelphia International label, "The Three Degrees", spawned three hits: "Dirty Ol' Man" (which went gold in the Netherlands and Belgium), "Year Of Decision" (which made it to #13 in