Jawabanmu

2014-05-30T21:59:23+07:00
Diagonal alas =  \sqrt{ 12^{2} + 9^{2} } =  \sqrt{144+81} =  \sqrt{225}  = 15

tinggi balok =  \sqrt{ diagonal ruang^{2} - diagonal alas^{2} } =  \sqrt{ 17^{2} - 15^{2} } =  \sqrt{289-225} \\  \\  =  \sqrt{64} = 8

volume = p x l x t
volume = 12 x 9 x 8
volume = 864  cm^{3}