Right triangle and "b" are the legs of the triangle. If the incircle is tangent to the hypotenuse AB at point P, then denoting the semi-perimeter as "s", we have and , and the area is given by This formula only applies to right triangles. If an altitude is drawn from the vertex with the right angle to the hypotenuse then the triangle is divided into two smaller triangles which are both similar to the original and therefore similar to each other. From this: In equations, where "a", "b", "c", "d", "e", "f" are as shown in the diagram. Thus Moreover, the
Hyperbolic triangle In other words, the quantity in the paragraph above is supposed to be equal to 1. Trigonometric formulas for hyperbolic triangles depend on the hyperbolic functions sinh, cosh, and tanh. If "C" is a right angle then: We also have the following equations: The area of a right angled triangle is: also The instance of an omega triangle with a right angle provides the configuration to examine the angle of parallelism in the triangle. In this case angle "B" = 0, a = c = formula_18 and formula_19, resulting in formula_20. The trigonometry formulas of right triangles also give the