Yap.Town

の背の高さだ

is … tall

→ の
phrase Rare #30,456
is … tall 背の高さ literally means “height” and is used to describe how tall someone is.
JA: 私は父と同じくらいの背の高さだ。
EN: I'm about as tall as my father.

彼は彼女と同じくらいの背の高さだ。

He is as tall as she is.

僕はトムと同じくらいの背の高さだ。

I'm about the same height as Tom.

彼女は君とほとんど同じぐらいの背の高さだ。

She's almost as tall as you.

トムはお父さんと同じぐらいの背の高さだ。

Tom is about as tall as his father.