CREATE TABLE table_21282 ("Official Name" TEXT, "Status" TEXT, "Area km 2" TEXT, "Population" FLOAT, "Census Ranking" TEXT)

What is the official name of the land with an area of 276.84 km2?
SELECT "Official Name" FROM table_21282 WHERE "Area km 2" = '276.84'
SELECT "Official Name" FROM "table_21282" WHERE "Area km 2" = '276.84'