Answer:
The length of DE = 10 units.
Explanation:
Given the parallelogram ABCD.
The measure of m ∠ BAD = 120°
We know that diagonals of a parallelogram bisect each other, so
BE = DE
In other words, the diagonal AC cuts the diagonal AD into two equal parts (BE and DE), and vice versa.
as
BE = 10
Thus,
DE = 10
Therefore, the length of DE = 10 units.