As shown in the figure, AB is a semicircle, O is the midpoint of AB, C and D are on AB, and ad ‖ OC connects BC and BD. if CD = 62 °, what is the degree of ad? (  ) A. 56B. 58C. 60D. 62

As shown in the figure, AB is a semicircle, O is the midpoint of AB, C and D are on AB, and ad ‖ OC connects BC and BD. if CD = 62 °, what is the degree of ad? (  ) A. 56B. 58C. 60D. 62

Take AB as the diameter to make a circle, as shown in the figure, make the diameter cm, connect AC, ∫ ad ∥ OC, ∧ 1 = ∧ 2, ∧ arc am = arc DC = 62 °, the degree of ∧ arc ad is 180 ° - 62 ° - 62 ° = 56 °, so select a