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: An angle inscribed in a semicircle is always a right angle.

                EXAMPLE: In triangle ABC \angle C=90\degree

Step 4: Find the two remaining angles.

            NOTE: The sum of the three interior angles is equal to 180.

              EXAMPLE: From triangle ABC

                                    \angle A+\angle B+\angle C=180\degree

                             \angle A\degree+\angle B+90\degree=180   


Step 5: Understand the hint given in the question to find the unknown angles.    

                EXAMPLE: HINT: ∠\ CAB\ =\ 2\ \cdot∠CBA\ or   \angle A = 2 * \angle B

                                     So,   \angle A + 2 * \angle A = 90

,                                                 3 * \angle A = 90

                                                   \angle A = 30\degree