A building pursuing the Development Density and Community Connectivity credit is located within a 2 acres community (8,093,m²), in which existing buildings total 90,000 sq. ft (8,361 m²). How large does the building need to be in order to comply with Option 1 of the credit?

The answer is: 30,000 sq. ft. (2,787 m²)

I'm assuming this is so because the minimum density is 60,000, and the building density times the acres would meet this requirement- however, I see no such calculation formula in the reference guide. If someone could explain the concept behind this, I'd be grateful!