Keliling sebidang kebun 150 m. Perbandingan panjang dan lebar kebun adalah 9 : 6. Luas kebun = ... m2

Dik :
k = 150 m
p : l = 9 : 6

Dit : L = ...?

Jawab :
misal : p = 9a, l = 6a
k = 2(p+l)
150 = 2(9a+6a)
150 = 2(15a)
150 = 30a
[tex]a = \frac{150}{30} \\ a = 5cm[/tex]
p = 9a
p = 9 × 5
p = 45 cm

l = 6a
l = 6 × 5
l = 30 cm

L = p × l
L = 45 cm × 30 cm
L = 1350 cm²

P+L =9+6=15
K =150
P = 1/2 x 150 9/15
P = 45
L = 1/2 x 150 6/15
L = 30
Luas = pXl
= 45x30
= 1350