What did the baby tree say to the mommy tree?
Geometry (gee, I'm a tree).
Sorry about that. Sometimes junk like that just slips out.
Anyhow, it is really helpful for young children to be able to identify shapes. To help your child learn (while playing), play I Spy: Geometry.
To play, simply find an object that is visible. Give a clue about the shape. The other person gets to guess what you are describing.
I see something oval.
I see something oval that is cushy.
I see something oval that is cushy, cream, and green.
(By the way, the answer is: the cat bed)
Take turns trying to stump each other!