In the diagram above, AO is perpendicular to OB. Find x
A.
7.5o
B.
15o
C.
22.5o
D.
30o
E.
38.6o
Correct answer is D
4x + 3x + 2x + 90 =360° [angle at a point]
9x + 90 = 360°
9x = 360° - 90°
9x = 270
x = 270/9
x = 30°