Keliling persegi panjangpanjang 60cm, perbandingan panjang dan lebar 3 : 2 luas persegi panjang adalah??

panjang = 3X
lebar = 2X

keliling = 2 x (p + l)
k = 2 x (3X + 2X)
60cm = 2 x 5X
60cm = 10X
6cm = X

p = 3X = 3 x 6cm = 18cm
l = 2X = 2 x 6cm = 12cm

Luas = p x l = 18cm x 12cm = 216cm2

keliling persegi panjang = 2p + 2l
60 = 2 x 3y + 2 x 2y
60 = 6y + 4y
60 = 10y
6 = y
jadi
p = 3y = 3 x 6 = 18
l = 2y = 2 x 6 = 12
maka
luas = p x l
luas = 18 x 12
luas = 216 cm²