Respuesta :

72 ft.
there are 6 faces
2 faces are 3 by 6 which equals 36 because 3×6=18 and 18 ×2=36
2 faces are 3 by 2 which equals 12 because 3×2=6 and 6×2=12
2 faces are 6 by 2 which equals 24 because 6×2=12 and 12×2=24
and 36+12+24=72