The question is meaningless. Nine feet is a linear measure - a length. Square feet is a measure of area, not length.
The question is not meaningless. In the given sentence or in any other sentence the definite article is 'the'. There are three ARTICLES: a and an are Indefinite articles. The is the definite article.
Chat with our AI personalities
There are nine square feet in every square yard.
nine.
If it is nine feet by nine feet, then it is 81 square feet.
nine square yards.
There are 40 square yards in 360 square feet. (just divide square feet by nine to get square yards).