Reply To: Lesson 2 – Building A Continuum Of Measurement – Discussion

[Amy Johnson]

I was wondering about comparing a triangle to a rectangle. In sixth grade they are to learn about the formula for the area of a triangle. I remember in school I never could remember what those formulas were, especially a trapezoid’s. But now that I have had to teach it to my students more visually than I ever learned with I can’t not remember because I see the picture in my head.

Right Isosceles Triangle and Rectangle

Direct comparison would be to place one on top of the other.

Indirect comparison would be to iterate tiles on both

Direct Measurement would be to get a count of tiles- figure out how to count the cut tiles

Indirect Measurement would be to make calculations to find the missing measurement.

I would think doing this with various quadrilaterals would be beneficial before the triangle now that I have thought this example through.