Back مثلثات قائمة خاصة Arabic বিশেষ সমকোণী ত্রিভুজ Bengali/Bangla Specialaj ortaj trianguloj Esperanto Triángulo rectángulo especial Spanish Triangulus rectus praecipuus Latin काटकोन त्रिकोण Marathi Triângulo retângulo especial Portuguese 特殊直角三角形 Chinese
A special right triangle is a right triangle with some regular feature that makes calculations on the triangle easier, or for which simple formulas exist. For example, a right triangle may have angles that form simple relationships, such as 45°–45°–90°. This is called an "angle-based" right triangle. A "side-based" right triangle is one in which the lengths of the sides form ratios of whole numbers, such as 3 : 4 : 5, or of other special numbers such as the golden ratio. Knowing the relationships of the angles or ratios of sides of these special right triangles allows one to quickly calculate various lengths in geometric problems without resorting to more advanced methods.