Now Angles

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SWBAT measure and draw angles, and describe properties of angles.

Big Idea

Learn to be like Euclid in this lesson that’s all about measuring, constructing and apply concepts of angles.

Do Now, Brain Pop and Vocab

30 minutes

Do Now:

-Students will review key vocabulary like midpoint and congruent segments in order to solve a question.  Once students have the value for x, you can review with students how to check (by plugging in for each segment) their work. 


Graphic Organizer and Brain Pop Video:

-Students will have a chance to brainstorm key words that relate to angles, and also draw their own angle.  This graphic organizer provides you with a chance to tap into students’ prior knowledge of angles, and get a sense of students’ knowledge of vocabulary relating to this topic.  Formal definitions for these words are provided on the next page. 

-You can have students write in their responses for the arrows, and then review these words and definitions with the whole class.

-This video will help students to review key words relating to angles, and perhaps also hear words that may be new to them. 

Summary of Brain Pop!

-This FREE brainpop does not require a subscription.

-It reviews key terms relating to angles and shows them in real-world situations. 

-The vocab covered includes acute, obtuse, right, supplementary, and complementary.  All of the vocab words are included in the angle key words in the graphic below. 


Angle Key Words:

Students will then be introduced to key terminology including definition of angle, sides, and vertex.  There are two boxes in notes, one for students to record information for the already drawn angle (<XYZ) and another box for students to draw their own angle and then record information.

-To differentiate instruction, particularly for students with motor function issues, you may want to just include the box with <XYZ. 

-Then you can review all of the key terms that classify angles using the graphic organizer in student notes.

-A lot of these words are review for students but having a word definition and drawn picture will help to reinforce the key idea for each word.

- We usually measure the interior of angles, not the reflux angle.

-We will also introduce the idea of an angle measure which relates directly to the standard for this lesson – G.CO.1 – in which students are required to know precise definitions.  By establishing a connection between circles and angle measures, we are helping students to connect critical ideas in the geometry content. 

Activity, Homework and Exit Ticket

20 minutes


-Students will follow the steps to construct a congruent angle using their compass.  There is a resource video for teachers to play for students and also is a great tool for review or helping students catch-up who are absent from class.

-A challenge question is provided which asks students to look at the construction done by another student.  In this, auxiliary lines have been draw to show that there are really two congruent triangles, one for each construction.  This challenge question offers an opportunity for students to connect congruent angles with congruent lines and also, congruent triangles.  This question allows students to think more deeply about this construction and make connections to important geometry topics.

- We can ask students, "how can we verify that our constructed angles are congruent?" (MP 8)


Activity/Homework:  Students will be asked to finish activity in class, and any questions that are not finished will become homework. You may also want to ask students to work on creating flashcards of key vocabulary learned in today’s class.   


Exit Ticket:  Students will complete an exit ticket question that asks them to use the idea of an angle bisector and algebra to find the missing angle measurements.