Answer:
AOB is 39 degrees.
Step-by-step explanation:
Given that ∠DOE is 51 degrees we know that ∠AOE is 180 degrees as it is a straight line.
∠BOD is a right angle given the ∟symbol so therefore ∠BOD is equal to 90 degrees.
m∠DOE + m∠BOD = 141 degrees (because 51 + 90)
Therefore m∠AOB = 39 because 180 - 141 = 39
Straight angles are equal to 180! Hope this helped
