Triangle their internal angles, measured here in degrees. A triangle that has two angles with the same measure also has two sides with the same length, and therefore it is an isosceles triangle. It follows that in a triangle where all angles have the same measure, all three sides have the same length, and such a triangle is therefore equilateral. Triangles are assumed to be two-dimensional plane figures, unless the context provides otherwise (see Non-planar triangles, below). In rigorous treatments, a triangle is therefore called a "2-simplex" (see also Polytope). Elementary facts about triangles were presented by Euclid in books 1–4
The Three Degrees album for 15 years, Two further singles were released from the album, the re-recording of "Dirty Ol' Man" and new song "Hurry Hurry". In 1996 they released a new best of album, "Best & New Hits: When Will I See You Again", which included four re-recorded hits and six new songs. A seasonal album, "Christmas With The Three Degrees", was also recorded in 1998. This album included a cover of Wham's "Last Christmas", which was released as a remixed dance single which gave the group their 15th (and final) UK top 60 single, reaching #54. Scott, Holiday and Garrison continued