Kimberly Eavenson

Coleen Loomis

Tuesday Tech Class

Geometry Part 1 for 10^th or 11^th Grade

Lesson: 1.4 Angle Naming

Students in this class tend to be less motivated, or frequently struggle, in mathematics. Being able to name angles is a rudimentary skill in Geometry and if this skill is not mastered, confusion throughout the year will follow. These students prefer activities to sitting and watching the overhead projector. Therefore, these students will benefit from activities in The Geometer’s Sketchpad because, as it is a slower paced class, they can take longer and explore the activities more in depth and at their own pace. The students in this class have difficulties grasping abstract concepts, so most examples must be in, or related back to, the concrete where The Geometer’s Sketchpad can help create concrete examples in a more motivating environment.

Objective:

Targeted SOL: Geometry – G.3

Section 1.4 on Angles of the Unit on Points, Lines, Planes, and Angles in Geometry Book

• Given an angle with the vertex and endpoints of the segments labeled, students will provide the names for the angle using all the given letters
• Given a picture of a triangle that is labeled and the angle measurements, students will determine the degrees corresponding to each labeled angle
• Given a picture of adjacent angles with the measurement of the angles labeled and given the measurement of the outside angle and one of the inside angles, students will properly label the endpoints and vertex of the angle.

Materials:

Worksheet: “Angle Naming using The Geometer’s Sketchpad”

Quiz “Quiz 1.4 Angle Naming”

Computers (in Lab)

Colored Chalk/Dry Erase Markers

Colored Pencils provided for worksheet and quiz

Lesson Description:

IN THE CLASSROOM

On the board, draw an angle

Label the vertex

Ask student to name the angle

Add other letters for the segments of the angle

Show students how to name this angle with the three letters

Stress the fact that the letter corresponding to the vertex must be in the middle of the three letters

Show that order doesn’t matter except for the middle letter (ÐABC is the same as ÐCBA – write on board and underline!)

Draw an example with a triangle; label the vertices

Call on student volunteers to name the angle with the three letters

Ask if there are any questions

Now, draw adjacent angles on the board

Have students name the angles

Demonstrate the sum of the two adjacent angles equals the outer angle

AT THE COMPUTER LAB

Hand out worksheets and colored pencils

PART I – Refer to instructions on worksheet

Point out the angle has the same measurement, no matter the order of the letters

Check up on class after “Part I” is completed to make sure everyone understands

PART II – Refer to instructions on worksheet

Point out that mÐABD + mÐDBC = mÐABC!!! (m means measure of angle)

Check up on class after “Part II” is completed to make sure everyone understands

PART III – Have students exit GSP

Without the computer, have students individually label triangle in Part III

Give students final chance to ask questions at completion of Part III

BACK AT CLASSROOM

QUIZ – Have students clear their desks

Distribute Quiz - allow 15-20 min to complete, unless notice taking longer/shorter, then reevaluate

Collect Quizzes

Grade

Review on the board anything with class the following period if necessary

Evaluation Procedure:

Worksheet will be graded on completion only and will count as a classwork grade. Quiz will be graded on how well students were able to appropriately label the given angles and each blank will carry an equal weight. Students might grasp the concept using triangles but not adjacent angles, they might understand the order, but not the equality of angles, or they might incorrectly assume the equality in angles because of the same vertex. Look at overall results of the quiz to see what areas the majority of the class still has problems with.