What is being constructed based on the markings in the following

Step-by-step explanation:

Based on the markins, it's being constructed parallel lines.

When we construct parallel lines, we use a compass to have two equal angles.

The next step here is to measure the arc of the angle at vertex E, and then, with the compass we use that length to draw the equal angles at vertex C.

Therefore, the answer is parallel lines.

i would say c is the best answer, hope it's right!

good luck! =)

cutie~