Calculate area of rectangle
$I=\left[0,3\right] \times \left[0,8\right] $
$A=\int_{I}^{} \! 1d(x,y) \, $
Can someone give me hint, how to calculate area with the informations they gave me. I think I should use multiple integrals, but I am not sure how excatly I neet to determine borders with the help of given interval.
The region is a rectangle, so this is a simple iterated integral. The $x$ coordinate goes from $0$ to $3$, and the $y$ coordinate goes from $0$ to $8$. So you can either integrate $dx$ from $0$ to $3$ first, or $dy $ from $0$ to $8$ first, then integrate that result with respect to the other coordinate. This can simply be thought of as the area of a rectangle with length $8$ and width $3$.