To determine the correct step in the proof involving perpendicular and parallel lines, the previous steps or given conditions are necessary. The options provided in the question involve either perpendicular or parallel lines by definition. More context is needed to determine the correct next step.
It seems like you're referring to a geometric proof involving perpendicular and parallel lines. To determine the correct step, I need to know the previous steps or the information provided in the proof. However, based on the options given, it looks like you are trying to establish a relationship between lines. Let me break down the options:
- a. ap ― ⊥ ra ― by the definition of perpendicular lines
- b. tr ― ⊥ ra ― by the definition of perpendicular lines
- c. ra ― || pt ― by the definition of parallel lines
- d. tr ― || ap ― by the definition of parallel lines
If you have information about the previous steps or any given conditions, I can help you determine which option is the correct next step in the proof. Otherwise, it might be challenging to provide a specific answer without more context.