no.26 dan 27 pakai cara

1. 20 x 15 x 12 = 3.600 (A)
2. phi r^2 t = 22/7 x 10 x 10 x 21
      = 6.600 (B)

1. Luas permukaan balok= 2 x ((pxl) + (pxt) + (lxt))
                                        = 2 x ((20 x 15) + (20 x 12) + (15 x 12))
                                        = 2 x 720
                                        = d. 1440

2. Volume tabung= 22/7 x 10 x 10 x 21
                            = 314,285714 x 21
                            = b. 6600