bantu pakai jalan ya

lp =( 2 x luas alas )+(keliling alas x tinggi)
lp= (2 x 28 x 21 ) + ((28+28+21+21) x 15
lp = 1176 +1470
lp= 2646

-lp = 6 x luas alas
lp = 6 x 36 x 36
lp = 7776 cm²