Answer: If perpendicular lines intersect, then they form right angles.
Step-by-step explanation:
You take the first part, "perpendicular lines intersect", and add the "if" to it. Then, you take the second part, "to form right angles", and add the "then" in front of it to get your answer, "If perpendicular lines intersect, then they form right angles."
Hope it helps! :)
