what cross section will be if you cut a cube diagnol
If you cut a cube along a diagonal plane that passes through opposite corners, you will get a square-shaped cross-section. The square will have a side length equal to the diagonal of the original cube's face.
To find the diagonal of one face of the original cube, you could use the Pythagorean theorem. Let's say the original cube has side length 'a'. Then, the diagonal of one face would be:
d = sqrt(a^2 + a^2)
= sqrt(2a^2)
= a*sqrt(2)
So, the cross-sectional area of the square would be (a*sqrt(2))^2, which simplifies to 2a^2.