Introduction to Geometry: Points, Lines and Planes

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SWBAT create models to show points, lines and planes.

Big Idea

Students will create models of points, lines and planes after defining these key words.

Do Now and Intro to Euclid

25 minutes

Do Now

-Students will be asked to find the solution for two equations.  This skill is an important pre-requisite skill which will be utilized throughout the year.  I also find that it’s helpful to see which students are struggling with this, and which students are not.  It can give me a sense of who has strong algebra skills and who will need reinforcement of these skills throughout the year. 

Intro to Euclid:

-To start Geometry, I like to show a video of Euclid and the history of Geometry.  Students who may not love math are able to connect to the historical nature of this content, and all students can get a sense of how and when Geometry came about (a really, really long time ago!). Please note that the video says two points form a line - we should be careful to avoid confusing students about lines and line segments. 


-Students can answer the questions to the video and then you can review them with the entire class. 

-This video will help to introduce important information about the building blocks of geometry:  points and lines.  This is the basis for our first lesson.  

Vocab and Pair-Share

30 minutes

Intro to Basic Geometry Words:

-We will then use the scaffolded student notes provided to introduce the basic building blocks of Geometry.  Students can fill in the notes for each key word, and also use the diagram of Plane P to write an example.  

- This section of notes can be teacher-led with a focus on emphasizing correct notation for students.

-On the second page of student notes, we will introduce key vocabulary like coplanar and collinear by asking students to think of words that begin with “co.”  Some possible student responses could be cooperate, co-habitat or cooperative.  This is a great time to introduce students to the importance of “pre-fixes” in geometry.  In these words, coplanar and collinear, the pre-fix “co” means together, which can help students to remember that collinear means points on the same line, and similarly for coplanar. 

-Lastly, we will introduce the idea of intersection using diagrams from traffic signs.

- This lesson is a great place to use 2D and 3D manipulatives - and perhaps, involve students in determining what are appropriate manipulatives


-Students will work through examples #1-10 on page 2 of class notes with a partner.

-Depending on students comfort with the notation and identification process, you can ask students to write their answers on the board.  I often like to have students write the wrong notation on the board so that we can discuss how and why we’ve chosen specific notation for each term. 

-MP #4 and MP #6 can be found throughout this lesson.  MP #4 in the Activity, and MP #6 in the precise definitions that we are using to introduce key building blocks of Geometry.

Finish Notes, Activity and Homework

30 minutes