How can u classify all animalia kingdom categories? Especially Platyhelminthes!

There are several ways you can categorize things. This is an example of how I would put animals in order

1. Porifera (sponges) ... they consist of a simple cell arrangement

2. Coelenterata (e. g Jellyfish) have an actual tissue

3. Platyhelminthes they are more complex and have muscles

4. Insects. They have several organs that and a simple brain