The triangles are all required to be non-degenerate, meaning that they do not have all three vertices on a line.
en.wikipedia.org Two courses were used for the races, each equilateral triangles.
en.wikipedia.org Each of these is divided into smaller categories; triangles can be equilateral, isosceles, obtuse, acute, scalene, etc. while quadrilaterals can be rectangles, rhombi, trapezoids, squares, etc.
en.wikipedia.org These subunits are: the tip, dorsum, alae, sidewalls, columella, and soft triangles.
en.wikipedia.org There are several well-known formulas for the areas of simple shapes such as triangles, rectangles, and circles.
en.wikipedia.org