Question

which segment(s) are perpendicular to ab? segment dc and ec segments dc, ec, and fc segment fc only

Explanation:

Step1: Recall the definition of perpendicular lines

Perpendicular lines are two lines that intersect at a right angle ($90^{\circ}$).

Step2: Analyze the given segments

In the diagram, only segment $FC$ forms a right - angle (as indicated by the right - angle symbol) with segment $AB$. Segments $DC$ and $EC$ do not form right - angles with $AB$.

Answer:

Segment FC only