The Challenge: Create your very own ellipse using just a compass or technology (I did one below using the free desmos.com/geometry)
Materials Needed: Compass, increasingly large circles to trace or graphing technology.
Math concepts you could explore with this challenge: Circles, geometric construction, geometry, symmetry, vertices/intersections
See this neat visual from Matt Henderson!
Depending on how you use this activity, you may engage with different mathematical standards. I’ve listed possible connected math content above. Here are a few suggestions for how you might integrate the 8 mathematical practices. Feel free to add your own suggestions in the comments!
2.) Reason abstractly and quantitatively. Why is it that this construction creates an ellipse? What can you say about the intersections of increasing radii of the circles?
3.) Construct viable arguments and critique the reasoning of others. Prove that this will always create an ellipse or explain when it will fail.