tolong nomor 1 saja tolong segera

luas permukaan = 2(pl + pt + lt)
= 2((18 × 12) + (18 × 8) + (12 × 8))
= 2(216 + 144 + 96)
= 2(456)
= 912 cm²

LP = 2×(pl+pt+lt)
= 2×(18×12 + 18×8 +12×8)
=2×(216+144+96)
=2×456
=912 cm