1. DC is tangent to circle O at C. If ABC = 59◦ , BAC = 60◦ , and BCA = 61◦ , then what is the measure of ACD?
2. ABC is inscribed in circle O. We know ∠AOB = 110◦ , ∠AOC = 120◦. Find the measure of BAC.
3. As shown in the diagram, NM is the median of trapezoid ABCD and PQ is the median of trapezoid ABMN. We know AB = 5 and DC = 17. Find PQ.