👉 A word that relates to a triangle is "triangular." In classical geometry, a polygon with three sides is called a triangle. The word "triangle" refers to its shape and size, which can be classified as one of four different types (equilateral, equiangular, regular, or scalene). Triangulum, in the context of mathematical concepts, refers to a type of triangular number that begins at 1 and ends with n numbers. The nth triangular number is defined as follows
