 Beginning after the 2010 FIBA World Championship , all FIBA @-@ administered tournaments use a rectangular key 4 @.@ 9 meters ( 16 ft ) wide . From 1956 until 2010 , FIBA @-@ sanctioned tournaments used a trapezoidal key . The narrower end was on the free @-@ throw line , where it was 3 @.@ 6 meters ( 12 ft ) , while the wider end , at the end line , measured 6 meters ( 20 ft ) . 
