Used to refer to a person's height, often in contexts like forms, descriptions, or comparisons. Related to the expression 背の高い (tall).
See also: 背の高い
履歴書に背の高さを書いてください。
Please write your height on the resume.
彼は背の高さが足りなくて、そのチームに入れなかった。
He wasn't tall enough to join the team.
Compound of 背 (se, 'back, stature') + の (no, possessive particle) + 高さ (takasa, 'height'). A straightforward descriptive phrase.