Question
Analysis
This question involves finding the missing
angle. The main focus is on understanding the properties of parallel lines cut
by a transversal.
Key
Concept Explanation:
When two parallel lines are cut by a
transversal:
Same-side interior angles are on the same
side of the transversal and inside the two lines. The key property is that same-side
interior angles are supplementary.
Alternate interior angles are on opposite
sides of the transversal and inside the two lines. The key property is that alternate
interior angles are congruent.
Step-by-Step
Solution:
∵ AB ∥ CD ∥ EF (Given)
∴ AB ∥ EF (Transitive Property of Parallel
Lines)
∴ m∠FBA + m∠F = 180° (Same-side Interior Angles Theorem)
∵ m∠F = 128°
(Given)
∴ m∠FBA + 128° =
180° (Substitution)
∴ m∠FBA = 180° - 128° = 52° (Subtraction)
∵ AB ∥ CD (Given)
...