Add a for$-$loop that repeats $5$ times. For each iteration compute the length to be the $2$ times the current iteration $($i$.$e$.,5)$ times the base length, so that will result in lengths of $2,4,6,8,10.$ Store those values in the length array you previously setup. Also, for each iteration get the heat transfer rate by calling the "GetHeatTransferRate" function and store that result is stored in the heatTransferRate array.