Step 1:  Note down the given trigonometric ratio and remember the table of trigonometry.

            Formula:  The cosine (cos) of an angle in a right triangle is a ratio. It is the

        length of the adjacentleg (adj) divided by the length of the hypotenuse (hyp)

           GIVEN: \cos \theta = \frac{\sqrt{3}}{2}


Step 2: Use the table to identify the required angle, compare the values and degrees.

                 \cos \theta = \frac{\sqrt{3}}{2}

                 \theta = \cos^{-1} (\frac{\sqrt{3}}{2}

                 \theta = \cos^{-1} (\cos 30\degree)  ([math] \because see the table )

               \theta = 30\degree