Answer:
∠CGH
Explanation:
When two lines are crossed by another line, the angles in matching corners are called corresponding angles.
When the two lines are parallel Corresponding Angles are equal.
∠AFG and ∠CGH are corresponding angles.
The lines AB and CD are parallel, therefore m∠AFG = m∠CGH.
∠CGH and ∠DGH are supplementary angles.
Therefore m∠CGH + m∠DGH = 180°
Substitute m∠DGH = 54°:
m∠CGH + 54° = 180° subtract 54° from both sides
m∠CGH = 126°
Therefore m∠AFG = 126°.