Question

Sebuah balok luas alasnya 384cm^2 , luas bidang muka 300 cm^2 dan luas bidang kirinya 200cm^2 berapa volumenya dan jumlah panjang rusuk balok itu?

Answer 1

384 = p x l -> p = 384:l -> l = 384:p
300 = p x t -> t = 300:p = 300 l : 384
200 = l x t = (384 : 384:l) x (300 l : 384)
      = l x 300 l : 384 = 25 l² : 32
200x32 = 25 l² -> 6400 = 25 l² -> l = √6400/25 = √256 = 16 cm
l = 16 cm -> p = 384/16 = 24 cm -> t = 300x16/384 = 12,5 cm
Volume = p x l x t = 24x16x12,5 = 4.800 cm³
jumlah rusuk = 4(24+16+12,5) = 4x52,5 = 210 cm