Class video clips to reinforce geometric concepts set in real design or real world applications. Video makes it interesting and can make a difficult concept come to life. Students brains now a days are set up for visual streaming media so use it to your advantage.
A series of geometry games designed to develop spatial reasoning. Spatial reasoning takes many hands on activities to fully develop it. Then one must move it to paper and get a student to turn shapes in their head. Art teachers have plenty of ideas that can help with that.
American Mathematical Society suggestions on teaching high level math thinking at an elementary level using paper folding. The goal is graduation at 12th grade not just your grade level so you want to know what students are headed for.
List of Math literature books that develop math concepts to a problem solving depth. Having a list makes purchasing with district and campus discretionary funds easy. Most of these I used with Hispanic at risk students who were failing math. It cheered students on giving them hope and the stories were good. It's a good activity that parents could do with their child as well.
Origami is an extremely hands on way to experience geometry and develop spatial sense. The gradual folding of the paper makes different geometric shapes creating visual scaffolding for math problems finding shapes within a shape.It is application level of shapes and develops structural thinking at a deep level. It also teaches perspective. An origami model can be turned 360 degrees developing rotational visualization in the mind's eye.
Series of lessons emphasizing the relationships found in geometry from a NASA perspective. Numbers have relationships and in work it is the relationship between the numbers that matter the most. Relationships determine pathways and possibilities.
Having a defined thinking approach saves time. Using this one it covers geometry from at least 5 aspects ensuring a teacher does not do her favorite way all the time set children up for failure. Tests cover all 5 ways which are visualization, analysis, abstraction, deduction, and rigor. One of the problems in the curriculum is it leaves this aspect of math levels within a concept out but teachers are expected to find those levels and teach those perspectives.