user: Question: Name the number of area km 2 for population density is 87
Columns: ['Member State', 'Population in millions', 'Population % of EU', 'Area km 2', 'Area % of EU', 'Pop. density People/km 2']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['European Union', '494.8', '100%', 4422773.0, '100%', '112']
SQL:

assistant: SELECT "Area km 2" FROM "Table" WHERE "Pop. density People/km 2" = '87';