Question

Perbndingan pnjang & lebar sbuah prsgi pnjng berturut2 adlh 7 : 3 .dgn keliling 80 cm.maka Luas prsgi pnjng tsb adlh...

Answer 1

Keliling = 2p + 2l
= 2 (p + l)
= 2 (7x + 3x)
= 2 (10x)
= 20x

20x = 80
x = 80 / 20
x = 4

panjang = 7 * 4 = 28 cm
lebar = 3 * 4 = 12 cm

luas = 28 * 12
= 336 cm²

Answer 2

Kell = 2(p+l)
 80 = 2(7x+3x)
80:2 = 10x
 40  = 10x
x = 4

panjang = 7x = 7.4 = 28
lebar = 3x = 3.4 = 12

luas = pxl
        = 28x12
         =336