Finding the Measure of an Angle in Intersecting Lines

Two lines, Line 1 and Line 2, intersect at point O, forming four angles. The measures of three of the angles are as follows:

Angle AOB = $x$ degrees

Angle BOC = $2x$ degrees

Angle COD = $3x$ degrees

Given that the angle between Line 1 and Line 2 at point O is a straight angle, what is the measure of Angle AOB?