I find that teaching geometry vocabulary is about finding and creating a number of experiences where students use the words in context. We might look for examples in the environment or create art projects with a set number of specific shapes.
This unit focuses on the six words used to classify triangles. It includes a pre-assessment and post assessment with answer keys, vocabulary cards, and a foldable with the same vocabulary. The last two pages show some sample triangles on grid paper and blank 1/2 inch grid paper for your convenience.
I attached magnets to my vocabulary cards and displayed them on the side of a file cabinet where I could easily change the order of the words and have students match the definitions. I found this worked like an interactive anchor chart for whole group and small group review.
You can decide if you want to print just page 13 of the foldable and have students take their own notes, or if you want to print 13-14 back to back. I have students who can easily take their own notes at the beginning of third grade and those who have struggled by the end of fifth.
I find it helpful to have students draw triangles I model on grid paper. I show them how to use the corners in the grid to draw right angles. We talk about how to make the angle narrower and wider for acute and obtuse angles respectively. After some practice, we create art projects with a set number of different triangles.