Kak tolong pakai caranya nomor 28 dan 30

28 ) Luas permukaan =
= 2 × ( p × l ) + ( p × t ) + ( l × t )
= 2 × ( 18 × 12 ) + ( 18 × 10 ) + ( 12 × 10 )
= 2 × ( 216 + 180 + 120 )
= 2 × 516
= 1.032 cm2 ◇ B ◇

30 ) Volume =
= Volume Balok + Volume Prisma segitiga
= ( p × l × t ) + ( 1/2 × a × t × t prisma )
= ( 18 × 10 × 8 ) + ( 1/2 × ( 17 - 8 ) × 18 × 10 )
= 1.440 cm3 + 810 cm3
= 2.250 cm3 ◇ D ◇

28. LP= 2 (pl + pt + lt)
= 2 (18x12 + 18x10 + 12x10)
= 2 (216 + 180 + 120)
= 2 x 516
= 1032[tex] {cm}^{2} [/tex]