Jawabanmu

2014-05-11T11:06:21+07:00
LP= 2 X P X L  = 2 X 10 X 8 = 160
       2 X P X T  = 2 X 10 X 7 = 140
       2 X L X T   = 2 X 8 X 7  =  112
 

LP= 160+140+112= 412

:)
2014-05-11T11:11:26+07:00
Lp=(2 x 8 x 10)+(2 x 8 x 7)+(2 x 10 x 7)
   =160+112+140
   =412 cm^{2}