Last week I read about and worked with shapes. I had a lot of fun preparing images to differentiate the concepts of interaction and interactivity.
I learned that simple shapes can be powerful resources in education. Even (or mainly) for a non-visual teacher/learner, as myself, starting from basic shapes available in any drawing or painting software, you can develop interesting visuals to support learning. Shapes also help you think visually. That is to say, a resource that you should always count on during the teaching and learning process.
