THE CORRECT ANSWER IS (D). THE DEGREE MEASURE OF MINOR ARC AB IS T...

28. The correct answer is (D). The degree measure of minor arc AB is the same as the

degree measure of the central angle that forms it (

∠

AOB ). The key to this problem is

that OA

≅

OB. (Each of these two line segments is the circle’s radius.) Given statement

(1) alone,

DOAB must be equilateral, and all angle measures are 60°. Now, consider

statement (2) alone. Since OA

≅

OB, the angles opposite those sides are also

congruent—that is, m∠OAB

5

m∠OBA. Based on statement (2), both angles measure

60° and, accordingly, so does

∠AOB—the central angle that defines minor arc AB.