Jawabanmu

2014-04-04T15:10:50+07:00
P = ((2xl)-6)                          k=36 cm
K = 2p+2l
a. 36 = 2(2l-6)+2l
36 = 4l-12+2l
36 = 6l-12
6l = 36+12
6l = 48
l = 48:6
l = 8
p = (2l-6)
p = (2x8-6)
p = 10
b. L= pxl
L = 10x8
L = 80

2014-04-04T15:11:12+07:00
P = 2lebar - 6

Keliling = 2 (p+l)
36        = 2 (2l - 6 + l)
36        = 2 (3l - 6)
36        = 6l - 12
36 + 12 = 6l
48        = 6l
    lebar = 48 / 6
    lebar = 8

Panjang = 2l - 6
            = 2(8) - 6
            = 16 - 6
            = 10

Lebar    = 8cm


Luas = P x L
        = 10 x 8 cm
        = 80cm^2