Step 1: Recall all the theorems of the circle.


Step 2: Note down given values and examine the figure

Step 3: Identify the suitable theorem for the given question.

            NOTE: The Angle at the Center Theorem tells us that 

                           \angle MON = 2 * \angle MLN

Step 4: Use the theorem to find the unknown value.

              EXAMPLE:   \angle MON = 2 * \angle MLN

                                 \angle MLN = \frac{1}{2} * \angle MON

                                 \angle MLN = \frac{1}{2} * 98\degree

                                   \angle MLN = 49\degree