Jawabanmu

2014-06-11T18:50:56+07:00
2014-06-11T18:52:43+07:00
L= p x l 
210 = 30 x l
l = 210/30 = 7 cm

K= 2(p+l)
=2 (30+7)
=2 x 37
=74 cm