Angle and Degree Measure

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Objective

Students will be able to find angles on a coordinate plane.

Big Idea

Students will turn a locker combination into a secret math code (angles).

Warm-up

5 minutes

I include Warm ups with a Rubric as part of my daily routine. My goal is to allow students to work on Math Practice 3 each day.  Grouping students into homogeneous pairs provides an opportunity for appropriately differentiated math conversations. The Video Narrative specifically explains this lesson’s Warm Up- Angles and Degree Measure, which asks students to identify the angles created by the hands of a clock.

I also use this time to correct and record the previous day's Homework.

Introduction to Real Number Angles

20 minutes

This lesson begins with a quick review of quadrants.  Students finally get to see why quadrants are placed in this specific manner.  This is a bit of a hook for the lesson.   

Next, I give them the major vocabulary about angles in standard form on a coordinate plane. 

After they get a little experience with the most basic angles on a coordinate plane, I introduce them to coterminal angles.  We begin by look at the negative/positive version of a given angle.  For example, for 250o, we find the angle -110o.  I then make a bit of a show going all the way around from 250o to 610o and ask the students what angle that would be.  This blows their minds.  I ask them to find another positive and then a negative one.  We discuss how many total coterminal angles there would be (Math Practice 8).   Given this new information, I then ask them what numbers we can use for angles now and if there are any limitations thus connecting angle measures to the real number system. 

We do a few additional example as needed to ensure that everything gets it.

Locker Combination Activity

20 minutes

The next activity has the students turn locker combinations into degrees (Math Practice 4).  Students decide on a locker combination, turn it into the appropriate degrees, and then trade with their partner to decode their partner's degrees back into a combination.  As a reminder (I had to look this up), you have to pass the first number at least 3 times (going right) before you hit the first number.  Then you have to go left and pass the next number one time before hitting it.  Go right and stop on the final number without passing.  It is important to review this process with the students before beginning the activity.   

Exit Ticket

5 minutes

I use an exit ticket each day as a quick formative assessment to judge the success of the lesson.  

Today's Exit Ticket asks the students to list  three angles co-terminal with 100o.

Homework

This Homework asks students to sketch a couple angles, some of which are larger than 180o.  Next it asks students to identify some coterminal angles.  The extension activity in the homework asks students to find the angle measures that the small hand of a clock moves in time (Math Practice 1).  I have included a blank clock with the minutes marked to provide a physical model to those students who require some scaffolding.