Thermal expansion of each dimension of a solid

Main Question or Discussion Point

Hi, I am trying to work out how much each dimension of a solid (for instance an annular disc) made out of steel changes assuming that the solid is heated uniformly and is not constrained at any of its boundaries. Am I right in saying that, the linear expansion equation L = L_0 (1+ α ΔT) can be applied to each dimension individually or should the dimensions be considered related and/or the calculations are more complex?
Thanks,