Answer:
∠ AOB = 17.5°
Step-by-step explanation:
∠ AOB + 110 + ∠ COD = 180 ( sum of angles in straight line )
[tex]\frac{1}{3}[/tex] ∠ COD + 110 + ∠ COD = 180 ( subtract 110 from both sides )
[tex]\frac{4}{3}[/tex] ∠ COD = 70 ( multiply both sides by 3 to clear the fraction )
4 ∠ COD = 210 ( divide both sides by 4 )
∠ COD = 52.5°
Thus
∠ AOB = [tex]\frac{1}{3}[/tex] × 52.5° = 17.5°
