Question 763597
Let the Length, Width and Height be L, W and H metres

Top = L*W = 0.56   ------ eqn(1)
Front = L*H = 0.12 ------ eqn (2)
Side = W*H = 0.105 ------- eqn(3)

Multiplying the above 3 equations (we can do this because we know that none of the values are 0)

{{{L*W*L*H*W*H = (L*W*H)^2 = 0.56*0.12*0.105 = 0.007056}}}

Hence {{{L*W*H = sqrt(0.007056) = 0.084}}}

Now we can find L as {{{L = (L*W*H)/(W*H) = 0.084/0.105 = 0.8}}}

Length = {{{highlight(0.8)}}} meters.

:)