Step 2: Analyse the given question. Draw a figure from the given information.

    GIVEN: Angle between the bank of the river and way of the boat \angle CAB = 60\degree.

                            Traveled distance AC = 600 m

                    Determine the width of the river AB = ?

Step 2: Select the appropriate trigonometric ratio.  

              EXAMPLE: We need to find the width of the river(adjacent side)

                                So, take \cos\ A=\frac{adjacent}{hypotenuse}

                                              \cos60\degree=\frac{AB}{AC}=\frac{AB}{600}

                                                      \frac{1}{2}=\frac{AB}{600} (Since \cos 60\degree = \frac{1}{2})

                                                    AB=\frac{600}{2})

                                                    AB = 300

                                        The width of the river = 300 m