the ratio is: The trigonometric inverse function is: in which is the angle opposite the cathetus . The adjacent angle of the catheti is = 90° – One may also obtain the value of the angle by the equation: in which is the other cathetus. See also Cathetus Triangle Space diagonal Nonhypotenuse number Taxicab geometry Trigonometry Special right triangles Pythagoras Notes References Hypotenuse at Encyclopaedia of Mathematics Parts of a triangle Trigonometry Pythagorean theorem