The corners of each triangle are draggable, and it only works for angles in the first quadrant.

Here's a visualizer I made in Desmos to show to my students!

www.desmos.com/calculator/m...

If you made a measurement this past equinox and haven't submitted it yet, please do! I will include it and update the results accordingly.

If you find this project worthwhile or interesting, good news! There's another equinox in the spring!

sites.google.com/view/themeas...

With three measurers come three PAIRS of measurements. This means three independent calculations of Earth's radius.

Not unexpected, but participation is starting off slowly. I am hopeful that participation now will encourage more participation later. The best part is, every equinox's astronomical conditions are identical, so previous entries can still be part of the calculation!

We have three data points so far.

Happy 2nd day of Fall! Fortunately I had the day off today (Happy Rosh Hashanah) so I was able to process the data and crunch the numbers.

The results and data are available at my website now, but if you want to see a summary, read the thread!
sites.google.com/view/themeas...

🥳 First response! Thanks for participating!

Unfortunately, it's cloudy where I am today. I was prepared to take three classes outside to measure shadows! But I won't be able to contribute any measurements today. I'll try again in the spring!

Oh my goodness, these are awesome!

1. Find a flat, level surface
2. Set up a vertical ruler
3. Find true North (northern hemisphere) or true South (Southern hemisphere)
4. Wait for the equinox
5. Measure the length of the shadow at solar noon
6. Record the time of solar noon (UTC)
7. Go to the MEaSURE website and submit your data

Math teachers! I have your lesson plan for the next equinox...Monday, September 22.

Join a global experiment to calculate Earth's radius!
youtu.be/myvEWdLU_1E
#iteachmath #math #maths #teach

New short! First short, actually 😅
youtube.com/shorts/r9rtr...

@petraschwer.bsky.social Thank you for sharing my post! This experiment's first attempt was done with help from a school in Leinfelden-Echterdingen, not far from you!

Hello STEM teachers! As the school year wraps up and you begin to make plans for next year, I've got something you might like to check out!

This experiment can be done anywhere in the world, from elementary to advanced. See the video for details!
youtu.be/myvEWdLU_1E

To organize participation and distribute resources, I've built a simple website.

Whether you're curious or you want to participate, come check it out!
sites.google.com/view/themeas...

Hello! This is The MEaSURE Project.

I am organizing a bi-annual experiment among schools, students, and lifelong learners to measure Earth's radius.

Please watch this informational video. Consider participating, and spread the word!
youtu.be/myvEWdLU_1E