The height relates to its standing or hanging upright, and the breadth relates to the hanging itself, and the height of the hanging was taken in the breadth.
Related Commentaries of Exodus 38:18
Exodus 38:18
18 And the hanging for the gate of the court was needlework, of blue, and purple, and scarlet, and fine twined linen: and twenty cubits was the length, and the height in the breadth was five cubits, answerable to the hangings of the court.