Question

Use the diagram of trusses for a railroad bridge.

Answer 1

You should take off E and add C and D because perpenidcular bisector means not only does it form a right angle to the line, it also bisects it, or cuts it into 2 equal portions. Also, If you look at triangles BED and BEF, they are congruent as both have right angles and equal sides BE, and DE = EF. So, BD = BF.

E is wrong because you don't know if line AC is perpendicular to DA, nor do you know if it's parallel to DF. And you don't know if DA is parallel to BE either. You ONLY know that BE is the perpendicular bisector of DF.