Respuesta :

42/2 = 21

 21 = w +2w+3

21 = 3w +3

18 =3w

w = 18/3 = 6

 width is 6

 length = 6x2=12+3 = 15

6+6+15+15 = 42


 width = 6 m

 length = 15 m