Consider a rectangular sheet of solid material of length \( l = 9 \, \text{cm} \) and width \( d = 4 \, \text{cm} \). The coefficient of linear expansion is \( \alpha = 3.1 \times 10^{-5} \, \text{K}^{-1} \) at room temperature and one atmospheric pressure. The mass of sheet \( m = 0.1 \, \text{kg} \) and the specific heat capacity \( C_v = 900 \, \text{J\kg}^{-1}\text{K}^{-1} \). If the amount of heat supplied to the material is \( 8.1 \times 10^2 \, \text{J} \) then change in area of the rectangular sheet is: