の深さ

depth of

→ の
phrase Rare #29,766
depth of の connects the thing being described to its depth; 深さ can refer to physical depth or figurative depth, such as the depth of someone's feelings.
JA: このプールの深さはどれくらいですか?
EN: How deep is this pool?

雪は膝の深さだった。

The snow was knee-deep.

琵琶湖の深さはどうですか。

How deep is Lake Biwa?

われわれはその川の深さを測った。

We measured the depth of the river.

それは家族に対する彼の愛の深さを示している。

It shows how deeply he loves his family.

琵琶湖の深さはどれくらいあるの?

How deep is Lake Biwa?

欲の深さが彼を没落させた。

His greed brought about his downfall.