ANSWER
Midsegment
EXPLANATION
We have the triangle ABC.
From the triangle, we see that point E divides line BC into two equal halves. This is depicted by the double marks on each side of E.
We also notice that D divides line AC into two equal halves, depicted by the single marks on each side of D.
This means that D and E are midpoints of AC and BC respectively.
The line DE that connects points D and E is called the midsegment of the triangle ABC.
According to midsegment theorem, DE is equal to half the length of AB.
