A square pyramid is a pyramid with a square base. In this problem, this base is formed by the points B, C, D and E as illustrated in the Figure above. So, the correct answers are:
First. (BC←→ and DE←→)
This is indicated in Figure 1. As you can see, the red lines are parallel, that is:
[tex]\overline{BC} \ is \ parallel \ to \ \overline{DE}[/tex]
Recall that two lines are parallel if they are always the same distant apart in which case they are equidistant, that is, they never meet.
Second. (CD←→ and BE←→)
This is indicated in Figure 2. As you can see, the green lines are parallel, that is:
[tex]\overline{CD} \ is \ parallel \ to \ \overline{BE}[/tex]
