MATHEMATICS · Single correct · CBSE · Mathematics · Lines and Angles · Lines and Angles
Problem
Lines AB and CD intersect at O. The four angles, taken in order around O, are:
∠AOC = (3x + 10)°, ∠COB = (2y − 20)°, ∠BOD = (5x − 30)°, ∠DOA = (y + 50)°.
What is the value of x?
(a) 25
(b) 15
(c) 20
(d) 18