Answer:
20°
Step-by-step explanation:
Look at the attached photo.
∠a and ∠e are equal because they are vertical angles.
So, m∠a = 110°
Then, ∠f is an exterior angle to angles a and c. So,
m∠f = m∠a + m∠c
Substitute and solve.
130 = 110 + m∠c
m∠c = 20°
Then, ∠c and ∠d are vertical angles so they are equal.
m∠c = m∠d
m∠d = 20°
I hope this helps! Feel free to ask any questions!
