Polygons on the Coordinate Grid

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Objective

SWBAT draw polygons in the coordinate plane given the coordinates of the vertices and determine the length of a side joining points with the same first coordinate or the same second coordinate

Big Idea

A polygon is made up of line segments that connect the shape’s vertices. The vertices can be identified as unique points on a grid.

Think About It

7 minutes

Students work in partners to complete the Think About It problems.  After 3-4 minutes of work time, I ask for one student to share his/her work on the document camera.  We check his/her figure to be sure that the polygon is graphed correctly.  I have 1-2 students explain why we can't find the distance between points D and E.  

I make sure I tell students that they will eventually learn how to find the distance between points that do not have a common coordinate...just not in 6th grade.  

Intro to New Material

15 minutes

In this lesson, students will be asked to plot multiple points on a coordinate grid.  They will be asked to determine the length of a line segment with a grid by finding the difference between corresponding coordinates or by adding the absolute value of corresponding coordinates.  Students will also be asked to plot the vertices of a shape, identify the shape, and determine the side length of horizontal and vertical lines.

There isn't new content in this lesson.  It's a nice opportunity to reinforce all of the skills students have learned throughout the unit, and to have them practice in a new (engaging) way.  Because of this, for the Intro to New Material section of this lesson, I have students guide me through how to complete each problem.

The Visual Anchor from the previous lesson is helpful to have on hand.

 

Partner Practice and Discussion

15 minutes

Students work in pairs on the Partner Practice problems.  As they work, I circulate around the classroom.  I am looking for:

  • Are students correctly including all of the necessary components of a graph?
  • Are scholars correctly plotting the coordinate pair on the grid and labeling it?
  • Are students correctly identifying and/or plotting the given shape?
  • Are scholars correctly determining the distance of two points on the grid?
  • Are students applying the concept of absolute value to find the distance between two points in different quadrants?

I'm asking students:

  • How did you know to draw the coordinate pair in that particular place?
  • How did you know which shape you were plotting?
  • How did you determine how far one point was from the other?
  • How/when could you apply the concept of absolute value to find the distance between two points?

 

After 10 minutes of partner practice work time, students complete the check for understanding problem on their own.  I then cold call a student to share out the length and a different student to share out the width.

Independent Practice

15 minutes

Students work on the Independent Practice problem set.  As they are working, I am looking for and asking the same questions that I used during the partner practice section:

  • Are students correctly including all of the necessary components of a graph?
  • Are scholars correctly plotting the coordinate pair on the grid and labeling it?
  • Are students correctly identifying and/or plotting the given shape?
  • Are scholars correctly determining the distance of two points on the grid?
  • Are students applying the concept of absolute value to find the distance between two points in different quadrants?

I'm asking students:

  • How did you know to draw the coordinate pair in that particular place?
  • How did you know which shape you were plotting?
  • How did you determine how far one point was from the other?
  • How/when could you apply the concept of absolute value to find the distance between two points?

 

Closing and Exit Ticket

12 minutes

After independent work time, I show a problem that has been solved incorrectly on the document camera, and ask the class to help correct the work (I am sure to ask the student first - I tell the student that I think the entire class can learn from his/her mistake.  I make sure to publicly thank the student for his/her willingness to share and for allowing us all to learn from the mistake).

Students work on the Exit Ticket independently to end this lesson.