keliling persegi panjang 80cm. jika selisih panjang dan lebarnya 12 cm, maka luasnya
Matematika
fatir41336
Pertanyaan
keliling persegi panjang 80cm. jika selisih panjang dan lebarnya 12 cm, maka luasnya
2 Jawaban
-
1. Jawaban RexyGamaliel
K = 80
p - l = 12
p = 12 + l
K = 80
2(p + l) = 80
p + l = 40
12 + l + l = 40
2l = 28
l = 14 cm
p = l + 12 = 14 + 12 = 26 cm
L = p.l = 26 cm . 14 cm = 364 cm² -
2. Jawaban Nik001
p - l = 12 cm
p = l + 12 cm
Keliling = 2 x ( p + l )
80 cm = 2 x ( l + 12 + l )
80 cm = 2 x (2l + 12)
80 cm = 4l + 24
4l = 80 - 24
4l = 56 cm
l = 56 / 4
l = 14 cm
Lebar = 14 cm
Panjang = 14 cm + 12 cm = 26 cm
Luas persegi panjang
= p x l
= 26 cm x 14 cm
= 364 cm²