Rebecca Bussinger

SOL: 6.13 Estimate visually the angle measure of a given angle by using 45°, 90°, and 180° as referents, and use appropriate tools to measure the given angles; and measure and draw right, acute, and obtuse angles and

triangles.

Competency: Estimate visually the angle measure of a given angle by using 45°, 90°, and 180° as referents, and use appropriate tools to check

the reasonableness of the estimate.

Respect each other. Listen when the teacher is talking. Always ask questions. Be a good group member. Share ideas during discussion. Use a pencil on math problems. Keep working until your task is complete.

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Task Analysis 1. The words “degree,” “angle,” and “referent.” 2. Use protractors, straight edges, and angle rulers. 3. Recognize right, acute, and straight angles. 4. Declarative knowledge (parts of the angle). 5. Estimating

5.13 The student will measure and draw right, acute, and obtuse angles and triangles, using appropriate tools.

Identify the appropriate tools (e.g., protractor and straightedge or angle ruler as well as available software) used to measure and draw angles and triangles.

Draw right, acute, and obtuse angles, using appropriate tools. Measure right, acute, and obtuse angles, using appropriate tools, and identify their

measures.

Rationalization: Angles are used everyday by architects and engineers. You even use them when you want to draw pictures, make cards, or even when making or flying kites.

Word Problem: On our class trip to the park everyone got to fly a kite. Susie was the first person to get her dragon shaped kite in the air. What type of angle is Susie’s kite making with the horizon? Using 45°, 90°, and 180° as referents, estimate the measure of that angle.

Students will use pretzels to represent the three referents and estimate the given angle.

90°, 45°, and 180° red lines represent pretzels.

90°

45°

180 °

Students will draw in three referents to estimate a given angle.

180°

45°

90°

Students will use protractors to check the accuracy of their estimations.

Examples Nonexamples

Students will sort examples and non-examples using the Concept Mastery Diagram. Students will explain why each item is either an example or a non-example.

180°

45°

90°

15°

145+92=237

20

X 9

180

CONVEY CONCEPTKey Words

OFFER OVERALL CONCEPT

NOTE KEY WORDS

CLASSIFY CHARACTERSITICS

CONCEPT DIAGRAM

TIE DOWNA DEFINITION

PRACTICE WITH NEW EXAMPLE

EXPLORE EXAMPLES

Examples: Nonexamples:

Always Present Sometimes Present Never Present

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3

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2

3

Angle Estimation Measurement

Two rays

Common vertexMeasurement in degrees

Acute

Obtuse

Straight

Right

Circles

Curves

Ruler

More than 2 rays

Estimating angles is a type of measurement that always includes two rays, a common vertex, a measurement in degrees, and at least one referent angle.

Angle

Degrees

Right Angle

Acute Angle

Obtuse Angle

Protractor

Referent

90

45

180

Referent angles

SOL: 6.13bCompetency: Estimate visually the angle measure of a given angle by using 45°, 90°, and 180° as referents, and use appropriate tools to check the reasonableness of the estimate.

Look at the angle. Think about whether it is straight, acute, right, or obtuse.

Acute.

Draw in the closest referent angles. (45, 90, or 180)

Estimate the measurement of the given angle.

70

Check estimation by using a protractor.

SOL: 6.13bCompetency: Estimate visually the angle measure of a given angle by using 45°, 90°, and 180° as referents, and use appropriate tools to check the reasonableness of the estimate.

Look at the angle. Think about whether it is straight, acute, right, or obtuse.

Acute.

Draw in the closest referent angles. (45, 90, or 180)

Estimate the measurement of the given angle.

20

Check estimation by using a protractor.

SOL: 6.13bCompetency: Estimate visually the angle measure of a given angle by using 45°, 90°, and 180° as referents, and use appropriate tools to check the reasonableness of the estimate.

Look at the angle. Think about whether it is straight, acute, right, or obtuse.

Obtuse.

Draw in the closest referent angles. (45, 90, or 180)

Estimate the measurement of the given angle.

165

Check estimation by using a protractor.

Activity: Students will identify and explain similarities and differences of the two angle examples.

Example 1 Example 2

The given angle is an

acute angle.The given angle is an

obtuse angle.

•A given angle•Referent angles•Estimated measure in degrees•Accurate measurement with protractor

Students will be given a worksheet with several everyday shapes and pictures. Each picture will have a highlighted angle. (See Guided Practice Part 1)

Using the visual step-by-step process the students will estimate the measurement of the highlighted angles.

The students will then work in pairs to assess their own work by measuring angles using. (See Guided Practice Part 2)

Estimate.

Estimate.

Estimate.

Estimate.

Estimate.

Estimate.

Measurement.

Measurement.

Measurement.

Measurement.

Measurement.

Measurement.

The students will receive a worksheet that has 5 angles on it. They will be instructed to draw in referent angles, estimate the measure of the angle, and find the exact measurement using a protractor. (See Independent Practice Part 1.)

1. Estimate Measurement

2. Estimate Measurement

3. Estimate Measurement

4. Estimate Measurement

5. Estimate Measurement

Students will take part in a baseball game activity to apply their knowledge of measuring angles in a real life situation.◦ Students will go outside and determine the

measurement of angles between home plate and each base.

◦ In teams, the students will create word problems regarding the angles they have

found.

The teacher will assess students individually using the learning visual and the rubric. (See Rubric.) The student will be asked to complete each step, with prompting if necessary.

While students meet with the teacher one by one; the rest of the class will be look through magazines finding examples of angles. They will trace the angles into their math journals and identify the angles as acute, obtuse, right, or straight. Then they will follow the learning visual to practice estimating using referent angles.

Objective8/10 points for masteryStudent:

Accomplished Objective with no assistance (2)

Accomplished Objective with some assistance (1)

Did not accomplish objective(0)

Identify the competency studied.Estimating the measurement of angles using referent angles

Identify acute, obtuse, right, straight, and 45 angles.

Draw referent angles around a given angle.

Estimate the measurement of a given angle.

Check accuracy of angle measurement estimation using a protractor.