Answer:
The approximate area is 35 square centimeters
Explanation:
we know that
The cross section passing through the diagonal of opposite faces of the cube is a rectangle
so
the approximate area is equal to
![A=bh](https://img.qammunity.org/2021/formulas/mathematics/high-school/qu2hlsd4h6dsol8g456d6dwuk4nd06d6gz.png)
where
b is the diagonal of a face
h is the length side of the cube
we have
![b=7\ cm\\h=5\ cm](https://img.qammunity.org/2021/formulas/mathematics/middle-school/mj1jg8fbfxczmikujotux7y2ef6l310051.png)
substitute
![A=7(5)=35\ cm^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/fwztd0p4phr12oqizsmy8l8v637qya2413.png)