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


  1. Timon Piccini

    October 22, 2012 - 1:27 pm

    I can’t wait to find out the results! You definitely win based on my class today!

  2. 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.

  3. 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

  4. Dan Meyer

    October 22, 2012 - 3:06 pm

    Hey, you’re welcome to guess. Doesn’t mean I’m gonna confirm anything, though.

  5. 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.

  6. 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.

  7. Dan Meyer

    October 22, 2012 - 7:42 pm

    @eddi, did you measure everything by hand?

  8. 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?

  9. 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.

  10. VocabularySpellingCity Mayor

    October 23, 2012 - 5:35 am

    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.

  11. 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:


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

  12. 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.

  13. 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.

  14. Arnon Avitzur

    October 23, 2012 - 7:04 am

    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.

  15. Dave Major

    October 23, 2012 - 7:09 am

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

    … I don’t know, tilt your head :)

  16. 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 !

  17. 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.

  18. Amir

    October 23, 2012 - 12:12 pm

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

  19. Dave Major

    October 23, 2012 - 12:21 pm

    Currently just 9 ;-)

  20. 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

  21. Carol

    October 23, 2012 - 6:01 pm

    I got an error message also.

  22. Telannia

    October 23, 2012 - 6:36 pm

    I am getting an error message to and I tried two different browsers.

  23. 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.

  24. Amir

    October 24, 2012 - 7:04 am

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

    Reminds me of when I talk to students about oblongs. ‘That’s a rectangle’, they cry. ‘Actually it’s a rectangle that’s not square’, I respond. Much puzzlement ensues!

  25. a different Dave

    October 24, 2012 - 8:35 am

    I predict that the shape of the rectangles is going to be very heavily influenced by the shape of the canvas provided.

  26. Andrew Stadel

    October 24, 2012 - 7:54 pm

    That was the easiest thing I did all day!