Consider the Lines Perpendicular to a Transversal Theorem.
Yes
Practice makes perfect
The expression b ∥ a says that b and a are parallel. Let's draw the diagram and then we can reason about it.
According to the Lines Perpendicular to a Transversal Theorem, in a plane, if two lines are perpendicular to the same line, then they are parallel to each other.
From the diagram, we see that a and b are both perpendicular to d. Therefore we can say that b ∥ a.
