A circle centered at O is circumscribed about Triangle ABC as follows: What is the measure of BAC?
Angle COA = 360 - 2 (100) = 160
Angle CAO = (180 -160) /2 = 10°
And since BO = AO then angle BAO = (180 - 100) / 2 = 40
So....angle BAC = angle COA + angle BAO = 10 + 40 = 50°
