Answers:
- Choice A) Square
- Choice B) Pentagon
- Choice D) Trapezoid
- Choice E) Hexagon
- Choice F) Rectangle
- Choice G) Triangle
In other words, it's nearly everything except choice C (octagon).
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Step-by-step explanation:
Search out "Cross sections of a cube" and you'll see visual examples of what is possible.
Here are the list of possible cross sections
- Square
- Pentagon
- Trapezoid
- Hexagon
- Rectangle
- Triangle
A parallelogram is also possible, but that isn't one of the listed choices so we can ignore it. The triangle can either be equilateral or won't be, depending how the cross section plane is oriented.
Nearly every box is checked except for the octagon, because we simply don't have enough faces to get 8 sides needed for the cross section.