##
* *Reflection: Developing a Conceptual Understanding
Finding Perimeter and Area in the Coordinate Plane - Section 3: Cooperative Activity

The distance formula serves the same purpose as a ruler, right? But does it give the same information as a ruler does? Not exactly. I realized the need to clarify this when my students started measuring distances on their graph paper and wondering why the answer from the distance formula never matched what their rulers were telling them.

In the following video, I explain the distinction between coordinate units and real units in order to make an important connection between the output of the distance formula and what students see on their rulers.

*The importance of understanding units*

*Developing a Conceptual Understanding: The importance of understanding units*

# Finding Perimeter and Area in the Coordinate Plane

Lesson 11 of 14

## Objective: SWBAT use the distance formula to find perimeters and areas of geometric figures

## Big Idea: It's Gridlock. Trapped inside the coordinate plane, armed only with coordinate pairs and formulas, students must find perimeters and areas of triangles and rectangles.

#### Cooperative Activity

*40 min*

For this lesson, I divide students into groups of 3 to 4. Each student gets a straightedge, a calculator, a sheet of graph paper, and the Cooperative Activity_Perimeter and Area in the Coordinate Plane resource, and the Math Rubric. We review what it takes to get a 4 in each of the three rubric domains. I also explain that this section of the lesson will last 40 minutes and will be followed by a section in which students will have to solve similar problems on their own. Therefore, I explain, it is important to understand everything you do and retain it, not just complete it and forget it. So after I'm done preaching, I instruct students to get right to work on the assignment. Oh, one last thing, "Got questions?...read the directions"

During the activity I circulate the room making sure that students are engaged. This entails simple prompts to students like, "Explain to me what you're doing." or "How can you present your work in such a way that it would be self-explanatory to a 3rd person if they were reading your paper?"

At the end of the 40 minutes, I give students time to organize their work and get it ready for submission.

*expand content*

#### Independent Practice

*30 min*

This section is pretty straightforward. Transitioning from the last section, I have the students rearrange the desks into rows since this is an independent activity. I also have to transition the energy in the room from a more relaxed cooperative atmosphere to testing conditions. No talking, no off task behavior allowed.

I review the requirements for scoring a 4 in each of the 3 domains on the math rubric and then students get started on the Independent Practice_Perimeter and Area in the Coordinate Plane resource.

When 30 minutes have elapsed, I collect the papers.

Time permitting, I review the solutions to the activity so that students get immediate feedback on their performance.

*expand content*

##### Similar Lessons

###### Tools of Geometry Unit Assessment

*Favorites(8)*

*Resources(13)*

Environment: Urban

###### Finding the Distance or the Midpoint of a Line Segment on the Coordinate Plane

*Favorites(17)*

*Resources(9)*

Environment: Rural

###### End of Year Assessment

*Favorites(1)*

*Resources(12)*

Environment: Urban

- UNIT 1: Community Building, Norms, and Expectations
- UNIT 2: Geometry Foundations
- UNIT 3: Developing Logic and Proof
- UNIT 4: Defining Transformations
- UNIT 5: Quadrilaterals
- UNIT 6: Similarity
- UNIT 7: Right Triangles and Trigonometry
- UNIT 8: Circles
- UNIT 9: Analytic Geometry
- UNIT 10: Areas of Plane Figures
- UNIT 11: Measurement and Dimension
- UNIT 12: Unit Circle Trigonmetry
- UNIT 13: Extras

- LESSON 1: Origins of the Geometric Universe
- LESSON 2: Line Segments
- LESSON 3: Distances in the Coordinate Plane
- LESSON 4: Exploring Midpoint Quadrilaterals
- LESSON 5: Investigating Points, Segments, Rays, and Lines
- LESSON 6: Formative Assessment Day 1
- LESSON 7: Introducing Angles
- LESSON 8: Angle Measurements
- LESSON 9: Basic Constructions
- LESSON 10: Measuring to find Perimeter and Area
- LESSON 11: Finding Perimeter and Area in the Coordinate Plane
- LESSON 12: Geometry Foundations Summative Assessment Practice Day 1 of 2
- LESSON 13: Geometry Foundations Summative Assessment Practice Day 2 of 2
- LESSON 14: Introduction to Transformations