Integer triangle cosine equals 0, ±1/2, or ±1. The only ones of these giving an angle strictly between 0° and 180° are the cosine value 1/2 with the angle 60°, the cosine value –1/2 with the angle 120°, and the cosine value 0 with the angle 90°. The only combination of three of these, allowing multiple use of any of them and summing to 180°, is three 60° angles. Conditions are known in terms of elliptic curves for an integer triangle to have an integer ratio "N" of the circumradius to the inradius. The smallest case, that of the equilateral triangle, has
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