Optical Illusions

It is the final couple days of school so we are basically done with teaching and we are providing fun things for students to do.  I'm teaching one art class while the English teacher is teaching the other.  She does the usual drawing and I'm working with students to create optical illusions, mostly because I can't draw worth anything.

The best thing about creating optical illusions such as the one in this entry, is that it can be done with straight lines.

We started with something simple that didn't require much. we used a hand, straight lines, and a few curved lines to make it look as if the lines were painted across the hand.  I did this to introduce them to the concept.

The next thing we drew was a triangle similar to the one in the picture.  They started with three triangles, extended a couple of lines, erase the corners and voila, you have a wonderful triangle whose sides run into another.  They are often referred to as "Impossible Triangles".  A couple of students had a great time with it.

The third piece we worked on was a set of stairs going down into the paper.  Three students got to this one and had an absolute blast.  The hardest part was extending the stairs up so it looked like it went into the ground.  One person used red instead of black which gave it a really interesting look.  Another got so excited that she wanted to do more so I have to find some for her to do tomorrow.

I already plan to use an optical illusion where it looks like a square hole pushes down into the paper.  It is such a cool illusion.  I also have to figure out how to do a double triangle that looks like its made of the letter Z and the reversed Z.  I have an idea of how to do it but I will have to play with it tonight.

Students often find this really interesting and fun.  Yesterday, I took over a fifth grade class for an hour so the teacher could give make up tests.  They did fairly well but I discovered many of them are not that precise when they follow directions.  Its like they are in too much of a hurry but most of them managed to finish two different ones and they were happy with the results.

I can see where we can use this when I next teach two dimensional shapes in Geometry.  Imagine spending a day or two playing with optical illusions and relating them to the two dimensional shapes.  yeah.  Let me know what you think, I'd love to hear.