Reflection: Vertical Alignment Prove Slope Criteria for Parallel and Perpendicular lines - Section 1: Activating Prior Knowledge


At this point in the year, I am realizing that we've reached the home stretch of the geometry course. Students are beginning to fill out their course requests for next year. Many of them have requested honors algebra 2.

It dawns on me that, even though I am teaching Geometry, I have a responsibility to make sure that my students are prepared to succeed in Algebra 2. This unit could not have come at a better time. In this lesson, we are hitting on systems of equations and rational functions: two topics of great importance in higher algebra courses.

I am being very intentional about raising the level of sophistication when I introduce or discuss these algebra topics. For example, I really enjoyed introducing set notation and discussing what the solution set of a linear equation in two variables really encompasses. It was nice to see students understanding something that they thought they had known from Algebra 1 on a much deeper level. In the same way, it was nice to discuss why it makes sense that dividing by zero is undefined. 

So going forward, I realize that this unit on Analytic Geometry is a unit that I really want to treat as a Rites of Passage experience for students who are moving on to higher, more formalized levels of algebra after they leave my class. This will remind me to keep the level of sophistication and precision high and also to be explicit with students in telling them that this level of rigor will be the norm in their next course so start preparing now.


  Preparing for higher algebra
  Vertical Alignment: Preparing for higher algebra
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Prove Slope Criteria for Parallel and Perpendicular lines

Unit 9: Analytic Geometry
Lesson 1 of 7

Objective: SWBAT use analytic geometry to prove that non-vertical parallel lines have equal slopes and perpendicular lines have opposite reciprocal slopes.

Big Idea: X-Games?? In this lesson, students are gettin' extreme on the slopes...of parallel and perpendicular lines that is.

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perpendicular slopes
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