It's great to see all this straightedge and compass stuff turned into a game, and I absolutely applaud the developers for launching it.<p>The above math, plus some graph theory (biconnected components etc.) is what drove D-Cubed's DCM 2D component dated, which powered the sketcher portion of many parametric MCAD systems after D-Cubed's launch by John Owen in 1989. See his paper "Algebraic Solution for Geometry from Dimensional Constraints" referenced on the Siemens PLM site:<p><a href="https://www.plm.automation.siemens.com/en_us/products/open/d-cubed/references.shtml" rel="nofollow">https://www.plm.automation.siemens.com/en_us/products/open/d...</a><p>The original parametric CAD system, PTC's Pro Engineer (now Creo) predates that (1987) and had it's own numeric (Newton-Raphson) solver. John Owen's innovation of using Galois Theory combined with Graph Theory to solve straightedge and compass configurations was a significant technical advance at the time, and the DCM 2D component ended up powering most sketchers in the industry.<p>Disclaimer: I worked at D-Cubed 1995-2000.
I enjoy the game a lot, but I disagree that it has that much of educational value. Without pre-existing geometry knowledge (e.g. similar triangles; median, bisector, and altitude in an isosceles triangle) the way to solve puzzles is only to randomly screw around. The game then doesn't give any explanation why that solution works.
This one works on mobile browsers<p><a href="https://sciencevsmagic.net/geo/#0A1.N" rel="nofollow">https://sciencevsmagic.net/geo/#0A1.N</a>
This is the greatest game I've found this year. I've been craving this. The way geometry and trigonometry was explored a long time ago by playing with arcs and lines is just so so cool to me.
This is now my favourite mobile game!<p>It might be helpful to provide some background links on compass/straight-edge construction [1] and the famous problem of squaring the circle [2]<p>[1] <a href="https://en.m.wikipedia.org/wiki/Compass-and-straightedge_construction" rel="nofollow">https://en.m.wikipedia.org/wiki/Compass-and-straightedge_con...</a><p>[2] <a href="https://en.m.wikipedia.org/wiki/Squaring_the_circle" rel="nofollow">https://en.m.wikipedia.org/wiki/Squaring_the_circle</a>
the challenge for this style of app is to balance mathematical content with good UX/UI. It is tempting to sacrifice one for the other.<p>also from yesterday: <a href="https://news.ycombinator.com/item?id=13256222" rel="nofollow">https://news.ycombinator.com/item?id=13256222</a>
It's a little unfortunate that they don't accept my somewhat elaborate but ultimately correct solutions, if I find a way to create a perfect rhombus within a rectangle in Lwaytoomany Ealsowaytoomany, they should accept it at least, and give me 1 star for my effort!<p>Pretty fun so far though!<p>edit: So far, I've found two methods to find the center of a circle that they don't like. 5L E7 isn't <i>that</i> bad<p>>:(
It would be pretty mean to include a special challenge level for constructing a heptagon... but also funny. (The heptagon is not constructible[1].)<p>[1] <a href="https://en.wikipedia.org/wiki/Constructible_polygon" rel="nofollow">https://en.wikipedia.org/wiki/Constructible_polygon</a>
It would be nice to be able to move or get rid of the task completed box to review your solution and look for modifications. Then you could reset and replay. The inability to review after completing is annoying.
This is how geometry was ment to be tought- riddles to be solved, on your own, contemplating, in your own speed, getting harder, step by step.<p>Great applause to the devs.