The average of the base length of the trapezoid is given to be
[tex]\begin{gathered} \text{Average }=\frac{10in+6in}{2} \\ \text{Average }=\frac{16in}{2} \\ \text{Average }=8in \end{gathered}[/tex]Since the length of the rectangle, Daniel formed is equal to the average of the base lengths of the trapezoid
Hence,
The length of the rectangle = 8 in