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Have you ever wondered why there are 360 degrees in a circle? The reason goes back more than 4000 years, to ancient Babylon. 🔄 https://t.co/FCsuZhdt4H

11 14
2019-09-24

sin(2v) = 2*sin(v)*cos(v): Dynamic & modifiable illustration using equal areas. For a quick investigation for Ss (w/o ID appearing at the end): https://t.co/hIaGZcseR3.

65 150
2019-09-09

Playing around with pattern tiles again this morning and found something *super* cool!

I started by making this from ... (1/many)

6 11
2019-09-02

Here, a animation of 's problem posed earlier this week: https://t.co/bTIh6QYMcT.
How can we formally prove the sum of these 2 square areas = 4*R^2, no matter where the large points lie? 🤔

31 68
2019-08-30

Inspired by : For any RT, build a rectangle off its HYP so ratio of its L to W = 1:2. What is the measure of the pink angle? More importantly, WHY does this value NEVER CHANGE? https://t.co/wl2ZOWg42N

32 80
2019-08-25

SSS (Side-Side-Side) Congruence Dynamic via Transformational SAS & 1 other theorem. Question: Which one? 🤔 https://t.co/bdKZuzNJXK.

6 10
2019-08-23

When we build equilateral triangles off 2 sides of ANY TRIANGLE, another equilateral triangle surprisingly emerges! 😮 Why does this occur? 🤔Source: . Created with : https://t.co/lTfrId4Hik.

83 310
2019-08-16

Cycloids, the fastest path and other amazing properties 🚊🚊🚊
https://t.co/uDdBcmOgfb

156 369
2019-08-14

Similarity in Right Triangles: Dynamic Illustrations w/o Words. Created with : https://t.co/Tm8i9UPsgP. Shout out to for her suggestions to help me improve this 1st version: https://t.co/QZzxluxqsJ.

26 66
2019-08-13

The common external tangent segment connecting any 2 tangent circles has a length equal to the GEOMETRIC MEAN of the radii of both circles. 😯 How to prove? 🤔(Source: ). https://t.co/3RwqD4ki5M

26 73
2019-08-05

Suppose V = a triangle vertex, I = incenter, O = orthocenter, & C = circumcenter. Then ray VI ALWAYS BISECTS angle OVC! How can we formally prove this phenomenon true? (Source: ). https://t.co/rYmoDjwCNy

28 84
2019-08-03

Do you think you know everything about squares...?

Van Aubel's Theorem: the two segments are perpendicular and of equal length

https://t.co/Nhcf38z3qe

40 133
2019-07-30

Here, we have a right triangle with its incircle, excircle, & points of tangency to be shown. How can we prove the collinearity among the 3 points (shown at the end)? (Source: ). https://t.co/CGNxP7i5Hz

16 32
2019-07-30

Ts: Want to engage your Ss in active modeling fun? 3D has all the tools you need! And we can use to test modeling accuracy! 🙂 Re: getting started: https://t.co/tVhsrPTAcV.

12 49
2019-07-16

Exploring cube w/in in a beta version of coming soon to both & platforms. Love how we’ll be able to plot the intersection of both from INSIDE THE 😮

9 27
2019-07-02

Testing, testing! Round and around. Just a test!

1 21
2019-06-21

with can help make these ACTUAL REALITIES in our classes. If we live in a 3d world, why remain only in the 2D CP? https://t.co/tVhsrPTAcV

2 11
2019-06-17

Morley's Theorem - Dynamic & modifiable illustrator w/o words: https://t.co/se5j3nEutR. How to prove? 🤔

16 47
2019-05-18