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The Arizona STEM Acceleration Project

Equations of Circles Graphing Activity

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Equations of Circles Graphing Activity

A 10th grade STEM lesson

David Delikat

10-15-23

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Lesson Description

For this lesson students will be exploring equations of circles. The teacher will place a giant graph in the room and students will make a circular art design to put on the graph. Students will then create an equation to represent their creation on the graph and then create equations for their peers circular creations as well.

As an extension to the main activity students will report data on their individual creations. After sharing that data with their classmates they will analyze the data to analyze trends in what they as a class created.

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Notes for teachers

  • This lesson would come prior to introduction of equations of circles. If can be your lesson that you introduce this concept with but it works better as an application activity rather than an introduction activity.
  • This lessons takes place over a class period but can be taken home by students to complete.
  • Students can work individually or in groups for this assignment
  • You will need a wall to set up the giant graph
  • Creativity should be encouraged with student’s designs

List of Materials�FOR TEACHER

  • Butcher Paper
  • Marker
  • Tape

FOR STUDENTS:

  • Coloring Materials
    • Markers, Pens, Colors Pencils, Crayons
  • Colored Construction Paper
  • Scissors
  • Glue/Tape

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HS Geometry Standards

G.G-C.A Understand and apply theorems about circles.

G.G-C.A.1 Prove that all circles are similar.

G.G-CO.A.4 Develop definitions of rotations, reflections, and translations in terms of angles, circles, perpendicular lines, parallel lines, and line segments.

A1.S-ID.A.2 Use statistics appropriate to the shape of the data distribution to compare center (median, mean) and spread (interquartile range, standard deviation) of two or more different data sets.

Standards for mathematical practice

G.MP.1 Make sense of problems and persevere in solving them

G.MP.2 Reason abstractly and quantitatively

G.MP.4 Model with mathematics.

G.MP.6 Attend to precision.

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Objectives:

Students will be able to identify the components needed to create an equation of a circle

Students will be able to generate an equation of a circle given the circle on a graph

students will be able to create a circle on a graph given its equation

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Agenda [60-90 Minutes]

Prior to lesson [Set up] [10-15 minutes]

Review concept [or introduce if you need] [5-10 minutes] [25-30 if teaching initial lesson]

Introduction to activity [5 minutes]

Student creation time [20-30 minutes]

Students graph their circles [5-10 minutes]

Generate equations for their circle [10-15 minutes]

Wrap up Discussion [10-15 minutes]

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Prior to lesson [Set up]

On butcher paper, teacher will set up a giant graph to be put on a wall of the room. (You can also just put a graph on your white board or project one on the wall with your smartboard/projector if that’s easier.)

Domain and Range of [-20,20] works well but you can choose whatever scale you’d like

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Lesson review

Ideally this is an application activity that you use to reinforce/expand your student’s understanding of equation of circles. You can use this in conjunction with the introductory lesson if you wish. I also find that it works better as a stand alone activity (i.e. I teach equations of circles one day and then the next day we do this), but it works well either way!

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Intro/Driving Question/Opening

What components do we need to create an equation of a circle?

( ___ __ ___)__ __ ( ___ __ ___)__ = _____

Teacher Note: Have students reflect on prior knowledge and fill in the blanks (you can make this better on your board if you write it out the equation should end up like (x – h)2 + (y – k)2 = r2

Green is variables, yellow is functions, blue is exponents.

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Review concept

Teacher note: Can have students review what the purpose of each variable is. Can lead class discussion or have them go into desmos and explore what manipulating each variable does.

Discuss/review how you identify h, k and r on a graph, and how you would graph a circle given h, k and r.

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Hands-on Activity Instructions

Modifications

  • Suggested Group Structure: Individual
  • Introduce students to the giant graph
  • Tell students they will be creating a circular image that will be placed on the graph
  • Gives students time to create their image
  • Have students put their items on the graph
  • Tell students to create an equation of a circle that represents their item on the graph
  • Tell students to create an equation of a circle for 3-5 other student’s creations.
  • Have students discuss their thought process throughout creating equations for their circles and their classmates circles.

  • Could group students in groups and have them make equations for their group member’s creations
  • Have students through a paper or a dart at the graph to decide where they have to place it
  • Have a random number generator decide where students need to place it�
  • Prompting questions for students:
    • “What did you look for when making your equations?”
    • “How did you decide where to put your circle?”

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Hands-on Activity Instructions Pt. 2

Suggestions

  • Have students collect data on the coordinates, area, volume, color, material, theme, etc., about their individual creation and share that data with each other in a class google sheet/excel.�
  • From the data that is presented in the google sheets group students into groups and have them go through and generate trends, data and other analytics for the materials that they created. �
  • Students can choose what aspect of the data they want to analyze and present that to the class

  • This component can be a good introduction for students to learn and view data analytics in excel/google sheets and starting them on using these materials to function within math.

  • You can present students with basic formulas “=Average”, “=StDev”, “=frequency” and have them explore those functions along with how to turn the data into graphs and images for their presentation on what they analyzed.�
  • There are several videos that students can explore to analyze the data as well and ChatGPT can provide additional assistance to help students with what they want to do.

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End Result

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Assessment

Students should be able to generate an equation for their circle that they put on the graph and then an equation for 3-5 other classmate’s circles as well. Students can also be assessed on their effort for their creations as well as their contributions to class/group discussion regarding their process and thoughts for the equations of the circles that they generated.

For the data analytic portion students will be graded on their analysis and presentation of the material.

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Rubric

Criteria

Exceptional (5) - Excellent

Proficient (4) - Good

Basic (3) - Fair

Limited (2) - Needs Improvement

Inadequate (1) - Poor

1. Creativity and Artistic Expression

Highly creative, visually engaging, deep understanding of artistic principles

Creative, visually appealing, good understanding of artistic concepts

Somewhat creative but lacks depth, visual appeal

Lacks creativity and is visually uninteresting

Lacking in creativity

2. Equation of the Student's Image

Accurately represents the circular image, well-explained

Mostly represents the circular image, minor errors or incomplete explanations

Partially represents the circular image, significant errors or lacks proper explanation

Inaccurate representation, major errors, insufficient explanation

No equation or unrelated equation

3. Equations of Classmates' Images

Equations for all classmates' circular images accurately derived and well-explained

Equations for most classmates' circular images accurately derived with minor errors and adequate explanations

Equations for some classmates' circular images derived with significant errors or incomplete explanations

Equations inaccurately derived, major errors, insufficient explanation

No equations or unrelated equations

4. Overall Communication and Engagement [Discussion]

Actively engages in the discussion, effectively communicates ideas

Participates in the discussion and communicates ideas reasonably well

Participates but struggles to communicate effectively

Participates minimally and has difficulty expressing ideas

Does not engage in the discussion

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Differentiation

Students can work with a partner to generate equations of circles.

Can take additional time during the creation process to review with students who may need it.

Assist students with the placement of their circle to give them easy to work with coordinates

Break the activity up into smaller chunks for students who may need more scaffolding.

Remediation

Extension/Enrichment

Can give students equations of circles and have them try to guess which one you made the equation for.

Ask students to find the area of circles that were given

Ask students to find the distance between circles