maaf tulisan nya jelek kak,

jawab

panjang sebenarnya = Ps = 90m"
lebar sebenarnya = Ls = 40 m
panjang model = Pm = 54 cm
Lebar model = Lm

Lm /Pm = Ls/Ps
Lm = Ls/Ps x PM
Lm = (40 m/90 m) x 54 cm
Lm = 4/9 x 54 cm
Lm = 24 cm

Mapel : Matematika
Bab : Skala

Ps = 90 m = 9.000 cm
ls = 40 m = 4.000 cm
Pp = 54 cm
lp = x


Ps/Is = Pp/lp
9.000/4.000 = 54/x
9/4 = 54/x
9x = 54 × 4
9x = 216
lp = x = 24 cm