Answer:
It's a rectangular prism :)
Step-by-step explanation:
Well I automatically know this because,
it can't be a triangle since the left and right corners aren't angled with 3 sides like a triangle
It can't be a square pyramid because that would mean it is the shape of a triangle when folded with a square base
It can't be a cube because cubes have sides equal in length, while this shape when folded is long in length and short in width
So the answer is a rectangular prism! Rectangles have long lengths and short widths and if this shape is folded from 2D to 3D that makes it a prism.
Hope this helps! Have a meowgical day :)))
