Cathet is the side of the rectangular triangle, which adjacent to the corner of 90˚. The side opposite the direct angle is hypotenuse. Having data about other sides of the rectangular triangle or the values \u200b\u200bof the angles, you can determine the length of the unknown category.
Having the values \u200b\u200bof the length of the second category and hypotenuses, one can calculate the second catat on the Pythagora theorem. The length of the unknown category is equal to the square root of the sink of hypotenuse and the square of the second category: a \u003d √ (C²-B²). It is possible to determine the catat if one of the angles of the rectangular triangle are known, which is not 90˚. Suppose there is an angle value α. Then the sinus α will be equal to the ratio of an opposite category to the magnitude of the hypotenuse (Sin α \u003d b / c), and the cosine α-ratio of the adjacent category to the hypothenus value (COS α \u003d A / C). So B \u003d C * SIN α, a \u003d C * COS α. The values \u200b\u200bof cosine and sinuses, tangents and catangents of the corners are contained in Special Bradys Tables.If the value of the second angle is known, which goes to the cathelet A, the equation will take the following form: a \u003d C * COS β.
All these solutions are based on the Pythagoreo theorem and the definitions of trigonometric functions. Knowledge of ordinary algebra laws will allow solving almost any task from the geometry field.