CB = DE
Hatch marks, or slashes, through an angle or side indicate that the angle or side is congruent to another angle or side (that other angle or side will have the same no. of slashes). Every pair of congruence has a different number of slashes to avoid confusion with any other side or angle. For instance, if 4 sides had 1 slash mark through it, there were 2 pairs of sides that were congruent, anyone seeing the diagram would not be able to tell what the 2 pairs are. Hope this helps!