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2014-08-10T20:07:07+07:00
P1 = 60cm
l2 = 90cm
p2 = 60 - 10 - 10 = 40cm
l2 = 90 - 10 - x = 80 - x cm
perbandingan
60/90 = 40/80-x
2/3 = 40/80-x
160-2x = 120
2x = 40
x = 20cm
1 5 1
2014-08-10T20:12:09+07:00
60/80=90/x
kali silang 60x=7200
x=7200/60
 = 120cm (panjang karton)
panjang sisi bawah=120-90-10=20 cm.