From a corner of a cube, a smaller cube is cut out. What can you say about the surface area and volume of the remaining portion of the cube?
Volume changes but surface area is constant
Lets name the vertices of the portion cut out.
Faces ABDC, BEHD and ABEF which are part of the bigger cube are removed and due to this, new faces EFGH, AFGC and CGHD are formed. Therefore the surface area remains the same.
But since, a part of the cube is removed, the volume changes.