ABCD is a quadrilateral whose side AB is a diameter of a circle through A, B, C and D. If ∠ADC = 120°, then the measure of ∠BAC is?
Answer & explanation
Correct answer: option 1
∠ACB = 90° ( in semicircle)
∠ABC = 180° - 120° = 60° (cyclic quad.)
∠BAC = (180° - (90° + 60°)) = 30°