persegi Panjan ABCD. kelilingnya 84 cm perbandingan panjang dan lebar 4:3 berapa luasnya

panjang = 4x
lebar = 3x

keliling = 2x(p+l)
84 = 2.(4x+3x)
84 = 8x + 6x
84 = 14x
84:14 = x
6 = x

panjang = 4x = 4.6 = 24cm
lebar = 3x = 3.6 = 18cm

luas = p x l = 24cm x 18cm = 432cm²

semoga membantu

Jawab :

Perbandingan,
Panjang = 4
Lebar = 3

Keliling = 84cm
Luas = ?

Jadi,
Panjang,
4/2[p + l]
4/2[4 + 3] x 84
4/14 x 84
24 cm

Lebar,
3/2[p + l]
3/2[4 + 3] x 84
3/14 x 84
18 cm

Luas = p.l
Luas = 24.18
Luas = 432 cm²

Semoga membantu ^_^