Timeline for Why define the names of quadrilaterals so that some categories (rhombus and rectangle) intersect and some (kite and trapezoid) are disjoint?
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Mar 22, 2018 at 12:04 | comment | added | Chaim | @mweiss Please see my previous two comments. | |
| Mar 22, 2018 at 12:03 | comment | added | Chaim | @BCLC Apparently lots of people reach age 15 thinking that quadrilaterals are either rectangles or squares. So their system doesn't start with the bifurcation of right angles vs. non-right angles; it starts and ends with congruent or non-congruent sides. Their trouble in pulling back to broader categories, to includes squares as rectangles & exclude non-rectangular quads, is a psychological problem. But I intended to ask a more logical question. Given the fact that they're only finding out from me about kites, parallelograms, rhombi and trapezoids, what would be the most elegant way to go? | |
| Mar 22, 2018 at 11:55 | comment | added | Chaim | @BCLC I agree that all of these linked questions are related, but I think that this question about circles for ellipses etc. is partly about the fact that certain mathematical ideas arose in the less rigorous, less systematic thinking of ordinary people, and mathematicians later arrived on the scene and tried to make the best use of the materials to hand. Occasionally I have a student suggest that if x=4, then 2x=24, as if the algebra were a cryptogram. I suppose that such distinctions reflect the evolution of notation used first for arithmetic and later for algebra. | |
| Mar 21, 2018 at 12:05 | comment | added | BCLC | @mweiss What about this Why do we have circles for ellipses, squares for rectangles but nothing for triangles? ? | |
| Mar 21, 2018 at 12:04 | comment | added | BCLC | @mweiss Thanks for linking to my question HAHAHAHA | |
| Mar 20, 2018 at 4:55 | comment | added | mweiss | See math.stackexchange.com/a/2699714/124095, matheducators.stackexchange.com/a/13766/29, and math.stackexchange.com/a/650205/124095. | |
| Mar 19, 2018 at 19:37 | comment | added | guest | youtube.com/watch?v=-pouOzsRLJM | |
| Mar 19, 2018 at 16:55 | history | asked | Chaim | CC BY-SA 3.0 |