Special 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.
Saevitiam annonae incusante plebe statuit frumento pretium quod emptor penderet, binosque nummos se additurum negotiatoribus in singulos modios.WikiMatrix WikiMatrix