Question

Diketahui Luas persegi panjang 270 m^2. Perbandingan panjang dan lebar 10 : 3. Berapa kelilingnya?

Answer 1

P × l = 270
p/l = 10/3
p = 10/3l

10/3l × l = 270
10/3l² = 270
l² = 270 × 3/10
l² = 81
l = 9 cm

p = 10/3 × 9
= 30 cm

K = 2 (p + l)
= 2 (30 + 9)
= 2 (39)
= 78 cm