Saturday, August 15, 2015

2014-2015 Geometry INB Unit 6 (Triangle Properties)

Here is unit 6...
I've attached links to all downloads underneath their photos.

The pocket page and table of contents.

The unit self-assessment and interior angle theorem.  The previous year I made this page a simple activity to discover the triangle sum theorem.  I skipped that this year because my students already knew that the angles sum is 180 degrees.  Instead, I included a proof for the triangle sum theorem.

However, I should have re-done the activity for the exterior angle theorem.  Students struggled with it for the rest of the year.  Not that they had trouble applying it, but they had trouble identifying when they could apply it.  The next day we did isosceles and equilateral triangles.  I purchased the isosceles and equilateral triangles from Lisa Davenport on TPT.  Then we did the proof of the base angles theorem.

Here is the inside of the foldable.
 

Next we learned about triangle inequalities and midsegments.  It was at this point that I decided I waned students to have the problems they were working on in their notebooks.  Without the problems, they are just looking at a bunch of calculations, and they need the context to be able to study.  So I have the notes briefly stated, and then the problems.

Lastly, we learned about medians and the other points of concurrency.  I did medians in the same fashion as the midsegments with the notes and problems.  For next year, I'm going to teach students to just find the two parts of the medians using the 2:1 ratio.  It just gets to be way too much for them when there's the 2:1 ratio, and then sometimes they use 2/3 and other time times they use 1/3 to solve for the missing pieces.  They dread questions about medians because of that.  Never again.

For the other points of concurrency, I just put them all into one lesson because I don't see them having any major importance.  We put together a foldable, and I gave students diagrams of triangles with all of the angle bisectors and all of the perpendicular bisectors drawn.  We wrote out the theorems next to the diagrams.

Here is the inside of the points of concurrency foldable.

When I teach this unit next year, I want to incorporate more proof.  There is just way too much missed opportunity in this unit to further develop proof skills.  Maybe one or two proofs for each topic.  Perhaps I can help the students through a proof proving the theorem, and then have them work on a proof applying the theorem.

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