## [Help Wanted] Draw A Rectangle

Would you do me and a few Canadian math teachers a favor?

Go to this link and create a rectangle. Press “Share.” Just do it once. Pass the link to your students if you’d like extra credit. I’ll tell you what this is all about in a couple of days.

Thanks.

2012 Oct 25. The purpose and the results.

I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. More here.

1. #### Alex

October 22, 2012 - 1:29 pm -

Can we guess?

Because I reckon I know what you’re after, and I know you generally encourage people to put their cards on the tabe & get invested in a question.

But there’s always the chance that discussing your purpose would influence the rectangles people draw, so… yeah, I’m asking for permission first.

2. #### Sam

October 22, 2012 - 2:25 pm -

we had some students doing a very similiar experiment. i wonder if you are trying to achieve a similiar result. i will also wait until permission to guess what it is your looking for

3. #### eddi vulic

October 22, 2012 - 3:26 pm -

I did this with my students this morning; I can send you the results if you want. They were, for me, unsurprising; but the set-up (“This is what I did with other math teachers this weekend!”) was worth it. My students are still in suspense.

4. #### Rocky

October 22, 2012 - 5:30 pm -

My guess is…

You’re trying to figure out the goldilocks rectangle, not too wide, but not too squareish, in an effort to discover something phi-nominal. Phi-l free to delete this if you think it will skew the results… If its not what your going for, i’d like to borrow your data cause i thought of a similar experiment a few days ago but didn’t know how to pull it off.

5. #### Arnon Avitzur

October 23, 2012 - 5:26 am -

How come one can only draw rectangles that are aligend with the screen ? Why can’t you do a rectangle which is at a different orientation?

6. #### eddi vulic

October 23, 2012 - 5:34 am -

I had kids draw, then measure (in cm) then calculate the ratios. It only took about 5 minutes total for each class.

7. #### VocabularySpellingCity Mayor

October 23, 2012 - 5:35 am -

Hi,
I did it. But, I would like to point out that I just clicked on a suspicious link which is something that I spend a lot of time teaching students NOT to do.

It’s only because I’ve read you for awhile that I did it. Please be sure to include some education, at the reveal, about the risks inherent in clicking on unidentifiable content.

8. #### David Patterson

October 23, 2012 - 5:51 am -

I resisted the urge to try and skew the results by making a really ‘skinny’ rectangle off to one side. :)

Another interesting experiment would be to get people to draw a right triangle.

I posit that a majority would be similar to this:

|\
L_\

with the longer leg on the bottom. (I hope the spacing in this post is preserved.)

9. #### Jered

October 23, 2012 - 5:54 am -

Since you didn’t prohibit guesses, I guess this is an attempt to show that the average dimensions of what people consider a rectangle will show to be extremely close to a 1.618:1 (golden) ratio.

10. #### Dave Major

October 23, 2012 - 6:49 am -

Arnon: I considered making it like that, but the user experience took a dive when I tried it.

11. #### Arnon Avitzur

October 23, 2012 - 7:04 am -

Dave:
No complaints on my end :)
It really is only relevant based on question you (as a teacher/researcher) are trying to answer.
For example – if you wanted to know what is the typical (or prototypical) rectangle, then by limiting the drawing to only “screen-aligend” lines, you are missing an opportunity to see if students consider other orientations as rectangular (which is actually a known problem that students do not identify rectangles of that kind).

But, as I said – I don’t know what they goal of this was, so maybe the design is suitable.

12. #### Dave Major

October 23, 2012 - 7:09 am -

Knowing the question behind this, it would of been an interesting extra dimension.

13. #### Jocelyn Dagenais

October 23, 2012 - 7:39 am -

I would like to know what’s the programming behind these activities that Dave Major created.

Thank you !

14. #### Dave Major

October 23, 2012 - 9:20 am -

Jocelyn, it’s Javascript built off a Ruby on Rails backend. The graphics are mostly Raphael.js. Drop me a line if you want any more info.

15. #### Ginger

October 23, 2012 - 3:22 pm -

I’m getting an error message that starts like this:

Errno::ENOENT in Rects#index

Showing /var/www/railsapps/rectangle/app/views/layouts/application.html.erb where line #5 raised:
No such file or directory – /var/www/railsapps/rectangle/tmp/cache/assets/sprockets%2Fd585a06e2ee6203ccb04c8b84150d14d20121023-32745-ewt05k.lock

16. #### Jason Dyer

October 24, 2012 - 6:42 am -

I wonder how many people draw a square, just to be different?

I’m wondering how much the interface affects answers. I clicked twice intending to get something more rectangular but eyeballed wrong so it ended up square-ish, and rather than bothering with changing around my answer I just hit send.

Fun to note: there are places in the world that still follow original Euclid so that a square is not a type of rectangle. Would people from those locations shy away from the square-like rectangles more?

Bizarre to note: In Wales “squares” and “diamonds” (tilted squares, not rhombuses) are two different things.

17. #### Amir

October 24, 2012 - 7:04 am -