RightStart Geometry

The continuing saga of our adventures using RightStart Geometry and RightStart B. I have an 11yo and a 7yo who have average math ability.The 11yo has done Miquon, Singapore, RightStart Transitions, Level D and Level E; RightStart has saved her from a life a math phobia.

I try to update our adventures on Tuesdays, although sometimes it doesn’t get done until Wednesday. And sometimes we really haven’t done that much math, so I skip it entirely.


RightStart Geometry:

Lesson 123 Napoleon’s Theorem

The lesson starts with a brief history lesson (I didn’t realize that Napoleon was an amateur mathematician).

Then, on to the theorem itself: “If equilateral traingles are constructed on the outside of the three sides of any given triangle, then their centroids are the vertices of ....” Well, surprise! You get to figure it out for yourself.

Up to this point in RightStart Geometry, equilateral triangles have been constructed using a T-square and 30-60 triangle. Now we learn how to make an equilateral triangle with a compass (the mmArc compass).

The end of the lesson discusses generalizing -- first, what does it mean to generalize, then, what happens when we generalize about non-equilateral triangles.

Lesson 124 is about Pick’s theorem. Kid1 opened the book to it, looked it over, and asked if we could spend some time on Challenge Math instead. We’ve been working with decimals in Challenge Math for the past several days -- we’ll return to Pick’s theorem eventually.