Jawabanmu

2014-05-07T07:59:22+07:00
A. luasnya 1/2 x d1 x d2 = 1/2 x 24 x 18 = 216
b. 2xluas belah ketupat + 4xsisinya = 2(216) + 4(15x25)
         L = 432 + 1500 =  1932
2014-05-07T08:04:55+07:00
Prisma ABCD.EFGH
k = 60 cm
AC = 24 cm (AO = 24 : 2 = 12 cm)
t = 25 cm

AB (garis miring) = k : 4
= 60 cm : 4
= 15 cm

BO = √AB²-AO²
= √15²-12²
= √225-144
= √81
= 9 cm
BD = 9 x 2 = 18 cm

L.belah ketupat = AC x BD : 2
= 24 cm x 18 cm : 2
= 216 cm²

alas ada dua, yaitu atas dan bawah
216 x 2 = 432 cm²

L.prisma = (AB x t) x 4
= (15 cm x 25 cm) x 4
= 375 x 4
= 1.500 cm²