Answer: See bolded below
Explanation:
I am going to label each picture based on it's color.
For the yellow net, it is a rectangular prism. You can tell because when you fold the pieces together, it forms a rectangular prism. Also, all the parts fo teh net are rectangles.
For the green net, it is a square pyramid. For a square pyramid the base is a square. In the picture, the base is a square.
For the purple net, it is a triangular prism. For a triangular prism, it has a ractangle as a base. The purple shows a rectanlge base and triangle sides.
For the blue net, it is a triangular pyramid. A triangular pyramid has a triangle base. The blue has a triangle base.