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MP8: The Medians of a Triangle

15 Aug

How do you give students the opportunity to practice “I can look for and express regularity in repeated reasoning”?

SMP8 #LL2LU Gough-Wilson

When we have a new type of problem to think about, I am learning to have students estimate the answer first.

1 04-10-2016 Image002.jpg

2 Screenshot 2015-09-11 08.43.14.png

I asked for their estimate in two slightly different problems because I wanted them to pay attention to what was given and what was asked for.

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4 Screenshot 2015-09-11 08.43.07.png

Students then interacted with dynamic geometry software.

Centroid_1.gif

What changes? What stays the same?

Do you see a pattern?
What conjecture can you make about the relationship between a median of a triangle and its segments partitioned by the centroid?

As students moved the vertices of the triangle, the automatic data capture feature of TI-Nspire collected the measurements in a spreadsheet.

Centroid_2.gif

I sent another poll.

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6 Screenshot 2015-09-11 08.43.40.png

And then we confirmed student conjectures on the spreadsheet.

5 04-10-2016 Image004.jpg

And so the journey to make the Math Practices our habitual practice in learning mathematics continues …

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1 Comment

Posted by on August 15, 2016 in Angles & Triangles, Geometry

 

Tags: , , , , , ,

One response to “MP8: The Medians of a Triangle

  1. howardat58

    August 15, 2016 at 9:26 pm

    Now balance the triangle on its centroid. This will get them thinking!

     

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