What's happening?

Shapes are added to other shapes. Can you see what is happening? What is the rule?

Problem

Image
What's happening?

   

 

We started with this pentagon.

Added a triangle:

Image
What's happening?

Then another one:

Image
What's happening?

What would come next, and why?

 

Can you invent something like these for your friends to solve?



pdf is available here