Tolong nomor 5 pake cara Makasih

misalkan
panjang = x = y + 3
lebar = y

K = 2 × (p + l)
54 = 2 × (x + y)
54 = 2 × (y + 3 + y)
54 = 2 × (2y + 3)
54 = 4y + 6
4y = 54 - 6
4y = 48
y = 12

x = y + 3
x = 12 + 3
x = 15

jadi
p = 15 cm
l = 12 cm

L = p × l
= 15 × 12
= 180 cm²