user: Question: What is the land area of the RCM having a density of 21.1?
Columns: ['Regional County Municipality (RCM)', 'Population Canada 2011 Census', 'Land Area', 'Density (pop. per km2)', 'Seat of RCM']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Coaticook', 18847.0, 'km2 (sqmi)', '14.1', 'Coaticook']
SQL:

assistant: SELECT "Land Area" FROM "Table" WHERE "Density (pop. per km2)" = '21.1';