Answer:
∠ AOB = 36°
Step-by-step explanation:
Since OA is perpendicular to OC, then
∠ AOB + ∠ BOC = 90 , substitute values
6x - 12 + 3x + 30 = 90
9x + 18 = 90 ( subtract 18 from both sides )
9x = 72 ( divide both sides by 9 )
x = 8
Thus
∠ AOB = 6x - 12 = 6(8) - 12 = 48 - 12 = 36°
