Step 1: Take the formula of the tangent.

              FORMULA: The cotangent (cot) of an angle in a right triangle is a ratio.

              It is  the length of the adjacent leg (adj) divided by the length of

              the opposite leg (opp).


Step 2: Plug in the relevant side lengths in the formula.

            EXAMPLE: Opposite side to the angle C = BD

                                Adjacent side to the angle T = CB

                                                  = \frac{CB}{BD}

                                           \Rightarrow\cot C=\frac{15}{8}