Michael Borcherds
@mikegeogebra.bsky.social
CTO | GeoGebra
#edtech #geogebra #pyggb #webusb
#edtech #geogebra #pyggb #webusb
Reposted by Michael Borcherds
Barney Maunder-Taylor says a square-based pyramid is exactly twice the volume of a triangular-based one (same side length). He doesn't want the tedious trig approach to proving it though, he wants a more intuitive route. He'll try the usual proof by @geogebra.org instead #mathsjam
November 23, 2025 at 1:45 PM
Barney Maunder-Taylor says a square-based pyramid is exactly twice the volume of a triangular-based one (same side length). He doesn't want the tedious trig approach to proving it though, he wants a more intuitive route. He'll try the usual proof by @geogebra.org instead #mathsjam
Reposted by Michael Borcherds
📣 We’re excited to welcome you to the newly formed Association for Mathematics in Education!
After bringing together five long-standing associations, we’re proud to unite our communities, expertise, and energy under our new association.
Watch our welcome video: www.youtube.com/watch?v=1uLL...
After bringing together five long-standing associations, we’re proud to unite our communities, expertise, and energy under our new association.
Watch our welcome video: www.youtube.com/watch?v=1uLL...
Welcome to AMiE
YouTube video by Association for Mathematics in Education (AMiE)
www.youtube.com
December 1, 2025 at 12:33 PM
📣 We’re excited to welcome you to the newly formed Association for Mathematics in Education!
After bringing together five long-standing associations, we’re proud to unite our communities, expertise, and energy under our new association.
Watch our welcome video: www.youtube.com/watch?v=1uLL...
After bringing together five long-standing associations, we’re proud to unite our communities, expertise, and energy under our new association.
Watch our welcome video: www.youtube.com/watch?v=1uLL...
Reposted by Michael Borcherds
We’re looking forward to seeing everyone at MathsJam Gathering this weekend - follow along here to see what people are sharing, and use #mathsjam to share your favourite moments!
November 18, 2025 at 12:23 PM
We’re looking forward to seeing everyone at MathsJam Gathering this weekend - follow along here to see what people are sharing, and use #mathsjam to share your favourite moments!
Reposted by Michael Borcherds
After some confusing back and forth interactions, I've realized that "I moved the meeting back by 30 min" is interpretable as both:
- "moved earlier by 30 min", and
- "moved later by 30 min"
- "moved earlier by 30 min", and
- "moved later by 30 min"
November 3, 2025 at 8:47 PM
After some confusing back and forth interactions, I've realized that "I moved the meeting back by 30 min" is interpretable as both:
- "moved earlier by 30 min", and
- "moved later by 30 min"
- "moved earlier by 30 min", and
- "moved later by 30 min"
Reposted by Michael Borcherds
If anyone wants to try printing this and testing it in the real world, the model here might be more suitable: it has slightly rounded edges, and the faces are slightly inset to give more clearance when assembling it. https://skfb.ly/pzDKY
Third of a cube (assemblable, with clearance) - Download Free 3D model by robinhouston
This is exported from BurrTools with the following parameters: Unit size: 10.00 Bevel: 0.30 Offset: 0.1 Wall Thickness: 0.00 Tubes size: 0.05 Leave inside grooves: no Leave outside grooved: no Remove grooves in void: no - Third of a cube (assemblable, with clearance) - Download Free 3D model by robinhouston
sketchfab.com
July 29, 2025 at 4:35 PM
If anyone wants to try printing this and testing it in the real world, the model here might be more suitable: it has slightly rounded edges, and the faces are slightly inset to give more clearance when assembling it. https://skfb.ly/pzDKY
Reposted by Michael Borcherds
I spent hours yesterday (on a long plane journey) failing to solve Stewart Coffin's Four Fit puzzle. I tried everything I could think of, and nothing worked.
If you know the solution please don't tell me.
If you know the solution please don't tell me.
August 10, 2025 at 3:16 PM
I spent hours yesterday (on a long plane journey) failing to solve Stewart Coffin's Four Fit puzzle. I tried everything I could think of, and nothing worked.
If you know the solution please don't tell me.
If you know the solution please don't tell me.
Reposted by Michael Borcherds
// Here is some OpenSCAD code, if you want to understand how I made it, or to make your own:
r = 10;
h = 60;
module hex_prism(i) {
rotate([acos(1/sqrt(3)), 0, i * 90])
linear_extrude(height = h, center=true)
circle(r, $fn=6);
}
for(i=[0 : 1 : 3])
for(j=[i + 1 : 1 : 3])
for(k=[j + 1 : 1 : 3]) […]
r = 10;
h = 60;
module hex_prism(i) {
rotate([acos(1/sqrt(3)), 0, i * 90])
linear_extrude(height = h, center=true)
circle(r, $fn=6);
}
for(i=[0 : 1 : 3])
for(j=[i + 1 : 1 : 3])
for(k=[j + 1 : 1 : 3]) […]
Original post on mathstodon.xyz
mathstodon.xyz
October 14, 2025 at 10:30 PM
// Here is some OpenSCAD code, if you want to understand how I made it, or to make your own:
r = 10;
h = 60;
module hex_prism(i) {
rotate([acos(1/sqrt(3)), 0, i * 90])
linear_extrude(height = h, center=true)
circle(r, $fn=6);
}
for(i=[0 : 1 : 3])
for(j=[i + 1 : 1 : 3])
for(k=[j + 1 : 1 : 3]) […]
r = 10;
h = 60;
module hex_prism(i) {
rotate([acos(1/sqrt(3)), 0, i * 90])
linear_extrude(height = h, center=true)
circle(r, $fn=6);
}
for(i=[0 : 1 : 3])
for(j=[i + 1 : 1 : 3])
for(k=[j + 1 : 1 : 3]) […]
Reposted by Michael Borcherds
The first prototype came out better than I expected, though there's a lot of room for improvement still.
October 19, 2025 at 3:23 PM
The first prototype came out better than I expected, though there's a lot of room for improvement still.
Reposted by Michael Borcherds
August 30, 2025 at 2:47 AM
Reposted by Michael Borcherds
August 29, 2025 at 8:28 PM
Reposted by Michael Borcherds
- Tu sais utiliser Geogebra ?
- Oui, bien sur. Je l'utilise tout le temps pour réaliser des figures de géométrie un peu difficiles.
Mon utilisation réelle de Geogebra :
- Oui, bien sur. Je l'utilise tout le temps pour réaliser des figures de géométrie un peu difficiles.
Mon utilisation réelle de Geogebra :
September 12, 2025 at 8:28 PM
- Tu sais utiliser Geogebra ?
- Oui, bien sur. Je l'utilise tout le temps pour réaliser des figures de géométrie un peu difficiles.
Mon utilisation réelle de Geogebra :
- Oui, bien sur. Je l'utilise tout le temps pour réaliser des figures de géométrie un peu difficiles.
Mon utilisation réelle de Geogebra :
Reposted by Michael Borcherds
Yes to everything that has already been mentioned. Additionally, I use some geogebra constructions as well (especially for linear optics, nice interactive demos for images from lenses, and multi-sense-systems)
September 16, 2025 at 10:09 PM
Yes to everything that has already been mentioned. Additionally, I use some geogebra constructions as well (especially for linear optics, nice interactive demos for images from lenses, and multi-sense-systems)
Reposted by Michael Borcherds
La Esfenocorona es un poliedro convexo con 12 △ equil. y 2 □, 22 aristas y 10 vértices. De estos, en 2 inciden 2 △ y 2 □, en ese orden; en 4 inciden 3 △ y un □; en los 4 restantes 5 △. Es el sólido de Johnson J86.
#GeoGebra
ilarrosa.github.io/GeoGebra/Esf...
ilarrosa.github.io/GeoGebra
#GeoGebra
ilarrosa.github.io/GeoGebra/Esf...
ilarrosa.github.io/GeoGebra
October 12, 2025 at 11:05 PM
La Esfenocorona es un poliedro convexo con 12 △ equil. y 2 □, 22 aristas y 10 vértices. De estos, en 2 inciden 2 △ y 2 □, en ese orden; en 4 inciden 3 △ y un □; en los 4 restantes 5 △. Es el sólido de Johnson J86.
#GeoGebra
ilarrosa.github.io/GeoGebra/Esf...
ilarrosa.github.io/GeoGebra
#GeoGebra
ilarrosa.github.io/GeoGebra/Esf...
ilarrosa.github.io/GeoGebra
Reposted by Michael Borcherds
Sure thing! I wrote a blog post just for you which includes links to the STL files.
Pentagonal icositetrahedron puzzle
A puzzle on the faces of the pentagonal icositetrahedron with 3D models, STL files, photos, and video illustrations
peterkagey.com
October 6, 2025 at 1:34 AM
Sure thing! I wrote a blog post just for you which includes links to the STL files.
Reposted by Michael Borcherds
In-person tickets are selling fast for the MathsJam UK Gathering - join us (in-person or remotely!) for a weekend of recreational maths in a conference centre and meet others who also love maths! Details at www.mathsjam.com/gat...
October 2, 2025 at 11:43 AM
In-person tickets are selling fast for the MathsJam UK Gathering - join us (in-person or remotely!) for a weekend of recreational maths in a conference centre and meet others who also love maths! Details at www.mathsjam.com/gat...
Reposted by Michael Borcherds
As well as our monthly pub meetings, there are also bigger annual MathsJam gatherings - one in the UK around November, and one in Oceania (New Zealand) - for details visit https://mathsjam.com/gathering
October 5, 2025 at 3:01 PM
As well as our monthly pub meetings, there are also bigger annual MathsJam gatherings - one in the UK around November, and one in Oceania (New Zealand) - for details visit https://mathsjam.com/gathering
Reposted by Michael Borcherds
Tomorrow in Cal: The amazing e^x whose derivative is e^x. @geogebra makes these visuals so easy.
November 17, 2024 at 2:19 AM
Tomorrow in Cal: The amazing e^x whose derivative is e^x. @geogebra makes these visuals so easy.
Reposted by Michael Borcherds
I've been seeing ads for the Shashibo toy. It looked like a more elaborate version of the kaleidocycle, which is fun to make out of paper. Shashibo is a ring of pyramids that comes in the shape of a cube but can be rearranged into a variety of shapes....
December 1, 2024 at 2:28 PM
I've been seeing ads for the Shashibo toy. It looked like a more elaborate version of the kaleidocycle, which is fun to make out of paper. Shashibo is a ring of pyramids that comes in the shape of a cube but can be rearranged into a variety of shapes....
Reposted by Michael Borcherds
Hello @tmip.bsky.social et al.
Let me introduce my submission for the April Animation prompt of a 'Polyhedral Net'. I went with the type used for fishing, I hope you enjoy it.
#geogebra #mathanimations #mathsky #mathsanimationtmip
youtu.be/fCtsAXOo4NU
Let me introduce my submission for the April Animation prompt of a 'Polyhedral Net'. I went with the type used for fishing, I hope you enjoy it.
#geogebra #mathanimations #mathsky #mathsanimationtmip
youtu.be/fCtsAXOo4NU
The 'net' of a Polyhedron as a Stereographic Projections - TMIP Animation Challenge
YouTube video by Ben Cornish
youtu.be
April 7, 2025 at 11:55 AM
Hello @tmip.bsky.social et al.
Let me introduce my submission for the April Animation prompt of a 'Polyhedral Net'. I went with the type used for fishing, I hope you enjoy it.
#geogebra #mathanimations #mathsky #mathsanimationtmip
youtu.be/fCtsAXOo4NU
Let me introduce my submission for the April Animation prompt of a 'Polyhedral Net'. I went with the type used for fishing, I hope you enjoy it.
#geogebra #mathanimations #mathsky #mathsanimationtmip
youtu.be/fCtsAXOo4NU
Reposted by Michael Borcherds
#PythonGgb : courbe de Gosper, un poil plus alambiquée que la ligne de Hilbert...
Défi personnel, mais peu de plus value didactique par rapport aux usages séparés de #python et de @geogebra.
En classe, moins de spectaculaire, mais plus de géométrie dynamique !
geogebra.org/python/index...
Défi personnel, mais peu de plus value didactique par rapport aux usages séparés de #python et de @geogebra.
En classe, moins de spectaculaire, mais plus de géométrie dynamique !
geogebra.org/python/index...
December 7, 2023 at 5:14 PM
#PythonGgb : courbe de Gosper, un poil plus alambiquée que la ligne de Hilbert...
Défi personnel, mais peu de plus value didactique par rapport aux usages séparés de #python et de @geogebra.
En classe, moins de spectaculaire, mais plus de géométrie dynamique !
geogebra.org/python/index...
Défi personnel, mais peu de plus value didactique par rapport aux usages séparés de #python et de @geogebra.
En classe, moins de spectaculaire, mais plus de géométrie dynamique !
geogebra.org/python/index...
Reposted by Michael Borcherds
I made this @geogebra applet that lets you play with Johan Gielis's polar super-formula. You can use it to make interesting shapes like these. https://www.geogebra.org/m/pprqzpja
December 2, 2024 at 10:43 AM
I made this @geogebra applet that lets you play with Johan Gielis's polar super-formula. You can use it to make interesting shapes like these. https://www.geogebra.org/m/pprqzpja
Reposted by Michael Borcherds
Xa podemos empezar a desvelar cousiñas... <<¿Hasta dónde podemos llegar con GeoGebra?>> é o título da ponencia coa que nos vai deleitar @bancoche.bsky.social no IV Día GeoGebra de Galicia.
#ourense #15febreiro #diageogebragalicia @geogebra.org
#ourense #15febreiro #diageogebragalicia @geogebra.org
January 3, 2025 at 6:19 PM
Xa podemos empezar a desvelar cousiñas... <<¿Hasta dónde podemos llegar con GeoGebra?>> é o título da ponencia coa que nos vai deleitar @bancoche.bsky.social no IV Día GeoGebra de Galicia.
#ourense #15febreiro #diageogebragalicia @geogebra.org
#ourense #15febreiro #diageogebragalicia @geogebra.org
Reposted by Michael Borcherds
April 23, 2025 at 7:01 PM
Reposted by Michael Borcherds
Aquesta setmana els problemes del concurs d'@innovamat_cat estan ambientats en #GeoGebra i aprofitem per fer-li una mica d'homenatge a en Pep Bujosa, que va ser el primer que em va presentar el software! Sempre et tindrem present.
innovamat.com/contest/ca/con…
innovamat.com/contest/ca/con…
February 25, 2025 at 12:21 AM
Aquesta setmana els problemes del concurs d'@innovamat_cat estan ambientats en #GeoGebra i aprofitem per fer-li una mica d'homenatge a en Pep Bujosa, que va ser el primer que em va presentar el software! Sempre et tindrem present.
innovamat.com/contest/ca/con…
innovamat.com/contest/ca/con…