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Euclidea

Banno December 01, 2018 at 01:03 10875 views 37 comments
Euclidea

This sort of geometric reasoning is out of favour. It does not appear in modern curricula. But I think it is brilliant. There is so much exquisite beauty in the patterns of lines and circles.

Thoughts?

Comments (37)

Banno December 01, 2018 at 21:40 #232717
I have found this game quite addictive. Has anyone else tried it?

The answers are somewhere between cogitation and intuition.
unenlightened December 01, 2018 at 23:09 #232751
Looks like fun, but it's bedtime right now.
Banno July 09, 2021 at 05:51 #563724
Playing with this again, I'm stuck at 7.1

I know I've solved it before, but can't see it now.

Construct a square whose area equals the sum of the areas of the two given squares and all three have the common angle.
TheMadFool July 09, 2021 at 06:13 #563740
If anyone's interested in just tinkering around with geometry try Geogebra. It's a free app and comes complete with lessons in geometry (on the website).
Benkei July 09, 2021 at 06:14 #563742
Reply to Banno I got stuck regularly in this game and never finished it. I did complete that one about 2 years ago and just started it again and I'm stuck in level 2. :cry: BTW, from the same makers xsection! Which I did finish and I'm sure you will like.

I'll have a look if I accidentally remember how 7.1 goes.
TheMadFool July 09, 2021 at 06:16 #563744
Quoting Banno
Playing with this again


All work and no play makes Jack a dull boy. All play and no work makes Jack a grasshopper.
Banno July 09, 2021 at 06:28 #563750
Reply to Benkei The hypotenuse has to be the length of the sum of the two sides, but I can't see how to construct it.
Banno July 09, 2021 at 06:36 #563757
AH, I did it, but in an inelegant way. No L or E goal.
TheMadFool July 09, 2021 at 06:46 #563764
Side length of first square = x
Side length of second square = y
Side length of third square = z

x² + y² = z²

3² + 4² = 5²
Banno July 09, 2021 at 07:14 #563774
Reply to TheMadFool Yep. So construct a right triangle with sides equal to the tow squares; then the hypotenuse is the length of the desired square.
Benkei July 09, 2021 at 07:48 #563792
Reply to Banno Are you getting all the stars? I only got all the stars for beta and never got beyond theta level 1.
TheMadFool July 09, 2021 at 07:51 #563794
Quoting Banno
Yep. So construct a right triangle with sides equal to the tow squares; then the hypotenuse is the length of the desired square.


Pythagoras' theorem. :up:
Banno July 09, 2021 at 08:01 #563802
Reply to Benkei Nuh. I'm focusing on getting through them all, but go back to get more starts as well. I've got all stars up to ?7, and a few beyond that. I find the E hard to get.
Benkei July 09, 2021 at 08:06 #563806
Reply to Banno I just started again. Already stuck at 1.5. Can't understand how I ever got to theta! :sweat:
Banno July 09, 2021 at 08:07 #563808
Reply to Benkei Spoilers?
Jack Cummins July 09, 2021 at 08:16 #563813
Reply to TheMadFool Reply to Banno
I didn't enjoy maths as a child but I do remember finding the idea of Pythagoras' s hypothenuse triangle to be very exciting. I also do like the geometry of circles and lines too, but somehow got on so much better in exploring them in art, rather than in geometry lessons.
Benkei July 09, 2021 at 08:16 #563814
Reply to Banno Not for me thanks. I remember that if you don't really understand why a solution works you'll get stuck again at a later point. So if someone explains it, I tend to not really understand why unless I figure it out for myself.
Banno July 09, 2021 at 08:17 #563816
Reply to Benkei I agree.
Banno July 09, 2021 at 08:17 #563817
Reply to Jack Cummins Try it out - see how you go.
TheMadFool July 09, 2021 at 09:07 #563840
Quoting Jack Cummins
I didn't enjoy maths as a child but I do remember finding the idea of Pythagoras' s hypothenuse triangle to be very exciting. I also do like the geometry of circles and lines too, but somehow got on so much better in exploring them in art, rather than in geometry lessons.


Art & Math go a long way back I believe: Proportio Divina.

Jack = 4 letters
Cummins = 7 letters

7/phi = 4.326 = 4

(7 + 4)/phi = 11/phi = 6.799 = 7

The gloves didn't fit O. J. Simpson!
Banno July 10, 2021 at 06:35 #564272
I'm stuck on 8.1

Anyone?
Benkei July 10, 2021 at 10:00 #564311
Reply to Banno Take the base line, extend it to the left with the length of the diagonal, extend it to the right with the vertical length, divide that total length by 2 and you have your point.
Benkei July 10, 2021 at 10:01 #564312
Meanwhile, still stuck on 1.5 :rofl:
Banno July 10, 2021 at 10:12 #564313
Reply to Benkei Oh, bugger. Half the total length, of course. Simple when you see it.

Solution to 1.5
[hide="Reveal"]Bisect the diagonal from bottom left to top right. intersection with top and base gives your points.[/hide]
Benkei July 10, 2021 at 10:27 #564315
Reply to Banno Yeah, I have that solution in my history but I no longer understand why this gives me the correct points. If I ignore 1.5 for now I can solve at least until 2.5 and ongoing.
Benkei July 10, 2021 at 10:30 #564318
2.7 with only 1 line is fun. I had to think about that again.
Benkei July 11, 2021 at 07:26 #564840
@Banno any hints for 4.11?
Banno July 11, 2021 at 07:41 #564846
Reply to Benkei My delta goes to 10??
Benkei July 11, 2021 at 07:53 #564849
Reply to Banno double checked but it really is 4.11. Maybe you need a certain amount of stars.? I have 24 in delta.
Banno July 11, 2021 at 08:53 #564866
Reply to Benkei I'm using the web site - are you on the app?
Benkei July 11, 2021 at 11:48 #564919
Reply to Banno Android app.
Banno July 12, 2021 at 05:50 #565525
Reply to Benkei Ah. SO it has extras.
Isaac July 12, 2021 at 16:54 #565742
Reply to Banno

This is fun, more distraction from actual work, so thanks for pointing it out. I'm stuck on 2.8 though, I can't get the 3E solution. One element has to be the tangent itself, so that doesn't leave enough elements for the way I was taught to do it (back when we inscribed all this on clay tablets, of course).

If anyone has any hints - without giving the actual answer, I'd appreciate a pointer.
Benkei July 12, 2021 at 17:34 #565753
Reply to Isaac You need two circles through the existing circle to get another point for the line which comes about from the intersection of the two circles. The first circle has to be placed correctly. The second circle's placement is dependent on the first.
Isaac July 12, 2021 at 18:00 #565764
Reply to Benkei

Got it! Thanks.
Benkei July 12, 2021 at 19:39 #565821
Reply to Isaac I have to admit, I've stopped caring about stars for ages. I'm happy if I manage to solve the question. Currently stuck at 8.6
Banno July 12, 2021 at 20:40 #565865
Reply to Benkei That's were I am, too - finding the point from which each side subtends an angle of 120° or 60°...