Answer:
A, D
Explanation:
Lines are parallel if consecutive interior angles at a transversal are supplementary.
Application
In the given figure, angles EAH and AED are consecutive interior angles associated with transversal AE. If they total 180°, then AC║EF.
Similarly, angles FCI and CFG are consecutive interior angles associated with transversal CF. If they total 180°, then AC║EF.
Either of these will prove AC║EF:
- ∠EAH +∠AED = 180°
- ∠FCI +∠CFG = 180°