Fast please!
Extracted text: A cyclic quadrilateral ABCD is circumscribing a circle having a center at point O. Angle AOC is 183'58'. If AB = 50 m., BC = 90 m. and AD = 70 m. Find the angle АВС. Select one: O a. 76 deg O b. 72 deg О с. 88 deg O d. 84 deg