Fill in the empty boxes as shown in the image below. Write and evaluate the definite integral that represents the area of the surface generated by revolving the curve on the indicated interval about the $y-$axis. $($Round your answer to three decimal places.$)$

$y=\frac{x^2}{2}+8,0x7$

$2{\displaystyle \underset{0}{\overset{\phantom{}}{}}}(\frac{x}{x})dx=$