Mathematics

Problem

At point

O

, four rays

OA

OB

OC

and

OD

are drawn in that order. The measures of three of the angles are

\angle AOB = 110^\circ

\angle BOC = 40^\circ

and

\angle COD = 30^\circ

. Which of the following conclusions can be drawn? a) Rays

OB

and

OC

form a straight line. b) Rays

OA

and

OD

form a straight line. c) Rays

OA

and

OB

form a straight line. d) No two of the rays form a straight line.