This Defining and Non-Defining Attributes of a Shape Bundle consists of two packets. It is a useful resource for teaching this somewhat difficult to understand concept.
Defining and Non-Defining Attributes of a Shape - Students practice sorting the attributes of a shape into either a defining or non-defining group. The set includes a color sort, which makes for a good center activity. It also includes lesson ideas and two student worksheet sorts.
Let's Learn the Defining and Non-Defining Attributes of a Shape Book - This book is a 16 page reader. Along with discussing the attributes of a shape it uses the analogy of attributes of a dog in order to help clarify students’ understanding of what attributes are.
I have a YouTube video available that walks through the introduction of the Defining and Non-Defining Attributes of a Shape packet. You might find this a helpful resource.
Here is the link: