Here is a page from Symmetry math journal @ Runde's Room. This is a joy to read. The teacher has taken such pride in creating a journal entry that is clean and structured. It allows comparisons both vertically and horizontally.

Symmetry anchor chart- a great idea for when kids start learning about symmetry to use as a reference sheet. I would have the class come up with symmetrical objects to add to it.

Interactive tool and foldable for studying angles- math journal page

100th Day Math {FREEBIES} | True Life I'm a Teacher

Math Ideas / math journal entry for types of triangles and sum of angles in a triangle

trying this as an experimental math journal tomorrow. hopefully i can incorporate this routine full on next year!