Di Ketahui

K = 2 (p + l)

44 = 2 ((3x + 4) + (2x + 3))

22 = 5x + 7

5x = 15

x = 3 cm

P = 3x + 4 = 3 ( 3 ) + 4 = 9 + 4 = 13 cm

l = 2x + 3 = 2 ( 3 ) + 3 = 6 + 3 = 9 cm

Luas

= pl

= 13 × 9

= 117 cm²

p = ( 3x + 4 ) cm

l = (2x + 3) cm

K = 44 cm

• Mencari nilai x

K = 2 ( p + l )

44 = 2 ( ( 3x + 4) + (2x + 3)

44 = 2 ( 3x + 4 + 2x + 3 )

44 = 2 ( 5x + 7 )

44 = 10x + 14

44 – 14 = 10x

30 = 10x

x = 30/10

x = 3

panjang = 3(3) + 4 = 13 cm

lebar = 2(3) + 3 = 9 cm

• Mencari Luas

L = p × l

= 13 cm × 9 cm

= 117 cm²

Luas persegi panjang adalah 117 cm²