This is a visual I hang up in my classroom which includes:
- 3 types of lines: parallel, intersecting, perpendicular
- 3 types of triangles: equilateral, isosceles, scalene
- congruent & similar
- sum of all angles: triangle & quadrilateral
All slides show a picture and example / definition. I print them out on legal size paper and laminate on poster board or construction paper. You can even blow them up if you choose.