We started our geometry unit with circles. Since my fifth graders didn't have much background knowledge on circles, I created this interactive foldable graphic organizer and poster set. I started out introducing the different part of the circle, so that they could then apply that knowledge to finding the diameter or radius when given the other one.
Here is the outside.
Here are several examples of what my students did on the inside.
These are the posters that they got their information from.
If you like this set, you can get it in my TpT store. Just click on the picture below.