u-cuy

Jawab :
Luas permukaan balok       =  2 x ( p x l +  p x t  + l x t )
                                        = 2 x ( 25 x 12 + 25 x 15 + 12 x 15 )  
                                        =  2 x ( 300 + 375 + 180 ) cm²
                                        =  2  x 855 cm²

                                                                                                                                                                                                                                                                                                = 1.710 cm²

Jawab :

Luas permukaan    = 2 x ( p x l +  p x t  + l x t )
                      22   = 2 x ( 3 x 2  + 3 x t  + 2 x t )
                      22   = 2 x  ( 6 + 3t + 2 t )
                      11   =  6 + 5t
                      5t    =  11 – 6
                      5t    = 5
                       t     = 1
Jadi tinggi balok itu adalah 1 cm.