A diptych is a painting with two panels and is considered as a single artwork.
A triptych is a painting with three panels and is also considered as a single artwork.
Generally, a polyptych is a painting with several panels. In all cases, it is considered as a single artwork.
You can upload a photograph of your polyptych to your application file so we can see the position of the respective panels in relation to each other. You can also upload a couple of photographs showing details of one or two panels of your choice.