 The key , in all games , starting with FIBA 's amendments to its rules in 2010 ( to be first implemented after the 2010 FIBA World Championship ) , is rectangular . Prior to 2006 , the key in FIBA @-@ sanctioned tournaments ( mostly basketball played outside the United States , and almost all international tournaments including the World Championships and the Olympics ) was trapezoidal in shape . Both NBA and FIBA keys are 16 feet ( 4 @.@ 9 m ) wide , while NCAA keys are narrower at 12 feet ( 3 @.@ 7 m ) . 
