tolong Jawab nomor 26,27,29 pakai cara

26][
Luas permukaan balok
= 2((p × l) + (p × t) + (l × t))
= 2((15 × 7) + (15 × 8) + (7 × 8))
= 2(105 + 120 + 56)
= 2 × 281
= 562 cm²

27][
Volume tabung
= πr² × t
= 22/7 × (35/2)² × 28
= 22 × 35²
= 22 × 1225
= 26950 cm³

29][
Volume gabungan
= Volume kubus + volume limas
= r³ + 1/3 × r² × t
= 15³ + 1/3 × 15² × (23 - 15)
= 15 . 15² + 8/3 . 15²
= (15 + 8/3) × 15²
= (45 + 8)/3 × 225
= 53 × 75
= 3975 cm³