Jawabanmu

2014-05-31T01:00:29+07:00
Keliling alas
c = a + b
   = (15)2 + (20)2
   =  225 + 400
   = 625
   = √625
   = 25

Luas = ( 2 x luas alas ) + ( keliling alas x tinggi )
         = ( 2 x 1/2 x d1x d2) + ( 25 x 4 x 35 )
         = ( 30 x 40 ) + ( 100 x 35 )
         = ( 1200 ) + ( 3500 )
         = 4700 cm 2
1 2 1