In the diagram above, AO is perpendicular to OB. Find x.
Attached Figure / Diagram
A
15°
B
22.5°
C
7.5°
D
30°
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
Since OA is ⊥ to OB
∴ ∠ AOB = 90º.
Hence, 4x + 3x + 2x + 90º = 360º (sum of angles at a point) 9x + 90º = 360º
9x = 270º;
x = 30º
Source: WAEC / JAMB / NECO Classroom Archive (Record #75857)