\(\[\begin{align} & \text{Temos:} \\ & \Delta L={{L}_{O}}.\alpha .\Delta \theta \\ & \text{Portanto}\text{,aplicaremos:} \\ & L-{{L}_{O}}={{L}_{O}}.\alpha .\left( \theta -{{\theta }_{O}} \right) \\ & 6-5,98={{5,98.1,4.10}^{-5}}.\left( \theta -20 \right) \\ & {{2.10}^{-2}}={{8,37.10}^{-5}}.\left( \theta -20 \right) \\ & 230=\theta -20 \\ & Logo: \\ & \mathbf{\theta }=\mathbf{210}\text{ }{}^\circ \mathbf{C} \\ \end{align}\] \)

A temperatura deverá ser de 210 graus Celsius.