Need help to make this
What exactly are you trying to make ? I see what looks like a pvc frame or a metal frame around a sleeping dog in a pet bed.
It has acrylic side panels
The pens are comprised of:
Take this picture to your local home improvement store and they can show you all the PVC pipes and connectors that you will need if you tell them the dimensions you want. Not sure, but it looks like they use plexiglass as the walls, so you will need mounts, hinges and such for that, too. It does look doable, Dorothy. Make sure you make it big enough that the dog has enough room to wander and play in.
Retail stores such as Industrial Plastics that carry boating and outdoor repair materials sell, and will cut to custom size, sheets of plexiglass.
Be warned, however, that it is expensive.
The cost of this project may be more than the dog is worth.
Here is an option that you just purchase. I bought one for my puppy. These come in different sizes. You can move them and use them in various places. They are easy to put together or take apart to store. These would work very well for a small dog. https://www.chewy.com/iris-4-panel-exercise-plastic
Here's a picture. Chewy has many options for you. Often on sale.
I agree w/ all the above comments. PVC pipes and T’s and angles.
I wouldn't want plexiglass, the dog would be bumping into it since they would have a hard time seeing the walls.