Answer
$\pi$/8
Work Step by Step
$\int$ $\int$ $x^{2}$ + $y^2$ dxdy
$\int$ $\int$ $r^3$ drdtheta
$\int$ $r^4$\4 dtheta
$\pi/8$

You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.