Fun With Angles

Designed by: Ashley Norton, Rosewood Elementary

Grade Level: 4     Subject:  Geometry

1) Curriculum Objective:  Identify and draw examples of right, acute, and obtuse angles with/without real world context. (4GS4-1 )

2) Overview:  Students will learn about right, acute, and obtuse angles in this hands-on lesson.  The teacher and students will use their arms to make the three angles.  They will use inch graph paper and a ruler to draw and label an example of each type of angle.  Then, the students will work in pairs and walk around the school property to find and draw examples of  the three angles.  The student pairs will use magazines, newspapers, and/or catalogues to locate examples of the angles and will use these pictures to illustrate this concept.  Expectations and an evaluation checklist are provided for this lesson.

3) Focus Question:  How can you use your school building, playground, and magazine, newspaper, and/or catalogue pictures to demonstrate right, acute, and obtuse angles?

4) Resources:

Copies of the culminating assessment for each student

Old magazines, newspapers, and/or catalogues

Rulers

Markers

Gluesticks for each student pair

Scissors for each student pair

Overhead projector

3 transparencies of inch graph paper  (Make a transparency of the template attached at the end of this lesson.)

3 copies of  inch graph paper per student (Make copies of the template attached at the end of this lesson.)

Overhead pen

Pencils

Math notebook

5) Culminating Assessment:

Students are to work in pairs to find examples of right, acute, and obtuse angles around school property and in magazine pictures.  The examples found on school property should be drawn on the corresponding page with the angle clearly marked.  Students should describe in a couple of sentences the location of the angle. (For example, if a student pair finds a right angle on the fence surrounding the school, the students should draw a picture of the fence, darkly shade in the right angle, and label it.  The students should then write a couple of sentences telling where they found the angle, "We found two fence posts that looked like a right angle. The fence posts are on the fence surrounding the playground.")  Student pairs are to find pictures from magazines, newspapers, and/or catalogues, cut them out and paste them on the corresponding pages of the culminating assessment.  Students are to trace over the angle with a marker to make it clearly visible.  A checklist will be used to evaluate this assignment.   

Checklist

Student #1__________________________________________ 

Student #2__________________________________________

1. Did the student pair draw an example of a right angle found on school property?

________ Yes (10 points)                   ________ No (0 points)

2. Did the student pair describe the location of the right angle found on school property?

________Yes (10 points) 

________Limited or incorrect information (5 points)   

________No (0 points)

3. Did the student pair draw an example of an acute angle found on school property?

________ Yes (10 points)                   ________ No (0 points)

4. Did the student pair describe the location of the acute angle found on school property?

________Yes (10 points)

________Limited or incorrect information (5 points)

________No (0 points)

5. Did the student pair draw an example of an obtuse angle found on school property?

________ Yes (10 points)                   ________ No (0 points)

6. Did the student pair describe the location of the obtuse angle found on school property?

________Yes (10 points)

________Limited or incorrect information (5 points)

________No (0 points)

7. Did the student pair provide an example of a right angle from a printed source, cut, paste, and label it on the corresponding page?

________Yes (10 points)

________Limited or incorrect information (5 points)

________No (0 points)

8. Did the student pair provide an example of an acute angle from a printed source, cut, paste, and label it on the corresponding page?

________Yes (10 points)

________Limited or incorrect information (5 points)

________No (0 points)

9. Did the student pair provide an example of an obtuse angle from a printed source, cut, paste, and label it on the corresponding page?

________Yes (10 points)

________Limited or incorrect information (5 points)

________No (0 points)

10. Based on teacher observation, did the student pair work together to gather and cite information contained in the culminating assessment?

________Yes (10 points)

________Limited or incorrect information (5 points)

________No (0 points)

Right, Acute, and Obtuse Angles on School Property

Draw a picture of the location of the right angle you found and describe where the angle was found.

Draw a picture of the location of the acute angle you found and describe where the angle was found.

Draw a picture of the location of the obtuse angle you found and describe where the angle was found.

Right Angle Found in a Picture

Acute Angle Found in a Picture

Obtuse Angle Found in a Picture

6) Instructional Activities:

Lesson 1 (60 minute block)

The teacher will hand out copies of the culminating assessment to each student and will divide the students into pairs according to ability levels.  The teacher will explain the expectations and grading scale to the students, making sure that they understand what is expected of them in this assignment.  Students should each receive 3 copies of the inch graph paper and a ruler.

 The teacher should explain that they are going to study 3 types of angles-right, acute, and obtuse.  Students should stand beside their chairs and be ready to make the angles with their arms.  The teacher will demonstrate each type of angle with his/her arms and have the students to copy the angle with their arms.  The teacher should make a right angle by holding bending the left arm at the elbow and holding the top portion straight up in the air.  The right hand finger tips  should touch the left elbow, making an "L."  The students should follow the teacher's lead and make the right angle with their arms.  The teacher should explain that they are making a right angle and that you  know it is a right angle because it looks like a capital "L."  The teacher should observe the students making sure everyone is making the angle correctly.

The teacher should now demonstrate an acute angle.  One way to remember this angle is to say, "An acute angle is a cute little angle."  The teacher should make an acute angle by bending his/her left arm at the elbow and holding the arm across the chest pointing toward the right shoulder.  The right arm should be bent at the elbow and the right hand finger tips should be touching the left elbow.  The students should follow this example and make an acute angle with their arms.  The teacher should observe the students making sure everyone is making the angle correctly.

The teacher should now demonstrate an obtuse angle.  The teacher should tell students that an obtuse angle is a large, stretched-out angle.  The teacher should demonstrate an obtuse angle by bending his/her left arm at the elbow and holding the arm across the left shoulder.  The right arm should be bent at the elbow and the right hand finger tips should touch the left elbow.  The students should follow this example and make an obtuse angle with their arms.  The teacher should observe the students making sure everyone is making the angle correctly.

Once the students understand how to make angles with their arms, they are ready to draw them on inch graph paper.  The teacher should have the overhead projector, inch graph paper transparency, ruler, and overhead pen ready.  The students should have their 3 sheets of graph paper, rulers, a pencil ready. The students should draw what the teacher draws on their graph paper.  On the first graph transparency, the teacher should take the ruler and pen and draw a straight horizontal line across the graph paper.  Then, take the ruler and pen and draw a vertical line that connects to the horizontal line. Draw arrow tips on the ends of each line and explain that it means that the line continues forever.  It should form a capital "L."  Ask the students if they remember the name of this angle.  Confirm that it is a right angle and tell them that a right angle measures 90 degrees.  Students should label the angle as a right angle and write that it measures 90 degrees on their graph paper. The student partners should check each other's work to make sure it is correct.

On the second graph transparency, the teacher should take the ruler and pen and draw a straight horizontal line across the graph paper.  (Remember to have the students drawing along with you.)  Then, the teacher should take the ruler and pen and draw a straight line that angles to the right.  It should look like a sideways "V."  Draw arrow tips on the ends of each line and ask the students what the arrow tips represent.  Ask the students if they remember the name of this angle.  Confirm that it is an acute angle and ask them if they think an acute angle measures more or  less than 90 degrees and ask them to give a reason for their response.  Confirm that an acute angle measures less than 90 degrees and you can remember that because it is smaller than a right angle. Students should label the drawing as an acute angle and write that it measures less than 90 degrees on their graph paper.  The student partners should check each other's work to make sure it is correct.

On the third graph transparency, the teacher should take the ruler and pen and draw a straight horizontal line across the graph paper.  (Remember to have the students drawing along with you.)  Then, the teacher should take the ruler an d pen and draw a straight line that angles out wide to the left.  It should look like a very stretched-out "V."  Draw arrow tips on the ends of each line and ask what the arrow tips represent.  Ask the students if they remember the name of this angle.  Confirm that it is an obtuse angle and ask them if they think an obtuse angle measures more or less than 90 degrees and ask them to give a reason for their response.  Confirm that an obtuse angle measures more than 90 degrees and you can remember that because it is larger than a right angle.  Students should label the drawing as an obtuse angle and write that it measure more than 90 degrees on their graph paper.  The student partners should check each other's work to make sure it is correct.  The students should place their 3 types of angles drawn on graph paper into their Math notebooks.

The teacher should make sure that students can identify the three types of angles before beginning the next activity.  The teacher should explain that the students are going to walk outside to find all three types of angles occurring in everyday objects. (For example, two fence posts may form a right angle.)  They should take their Math notebooks, a pencil, and a copy of their culminating assessment outside.  They are to work with their partner to find an example of each angle.  Students should record the angle's location and a crude drawing so they can write it on the culminating assessment in Lesson 2.  The teacher should begin by directing the walk and may need to point out a couple of examples of angles to the students so they understand the assignment.  The student pairs should walk around quietly so they do not disturb other classes and find their angle examples.  When they are finished they should return to class with their teacher.

Lesson 2 (60 minute block)

The teacher should review Lesson 1 with the students by having them make the 3 angles with their arms, looking at their graph paper drawings, and reviewing their information from the walk around the school.  The teacher should explain that the students are expected to complete their drawings and explanations of where the angles are found.  For example, if a group found a right angle occurring with two fence posts, then they should draw part of the fence and then shade in the fence posts so it is obvious in the drawing where the right angle is located.  Remind students to draw their angle in the correct place on the culminating assessment sheets.  The teacher and peer groups should offer suggestions and guidance if necessary.

While the students are working on this portion of the assignment, the teacher should be placing the magazines, newspapers, and/or catalogues, scissors, markers, and gluesticks on each groups table.  The students should use these materials to complete the last portion of their culminating assessment.  The teacher should remind the students that they are to find one example of each type of angle in the printed materials.  They should cut out the picture where the angle occurs, paste it on the corresponding page of the culminating assessment, and use a marker to trace over the angle.  The students should make sure the angle is clearly visible.   The teacher should be offering assistance and guidance as needed.  Once the student groups have completed the assignment, they can trade their assignments and look over each other's work.  Completed assignments should be turned into the teacher for evaluation.