ALEX Lesson Plan

     

Measuring Angles 

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  This lesson provided by:  
Author:Morgan Boyd
Organization:Retirement
  General Lesson Information  
Lesson Plan ID: 35675

Title:

Measuring Angles 

Overview/Annotation:

This lesson is designed to teach students to measure angles with a protractor. The student will be taught how to read the protractor correctly by using either the top or bottom set of numbers. The lesson will reinforce classifying angles as acute, right, and obtuse. The student will sketch angles given a specified measure.

This lesson results from the ALEX Resource Gap Project.

 Associated Standards and Objectives 
Content Standard(s):
Mathematics
MA2019 (2019)
Grade: 4
25. Use a protractor to measure angles in whole-number degrees and sketch angles of specified measure.
Unpacked Content
Evidence Of Student Attainment:
Students:
  • Demonstrate using a protractor to measure angles in different orientations to the nearest degree.
    Example: Given an angle, align the vertex of the angle with the correct point on the protractor, align one ray of the angle with the 0o mark on the protractor, and read where the other ray is located on the protractor.
  • Draw an angle of a given size using a variety of tools.
    Example: Draw a ray and use a protractor to construct a 108o angle.
  • Determine the angle measure when given an image of a protractor with angle rays intersecting the protractor scale.

  • Example: Given a protractor showing angle rays intersecting the protractor at 83 degrees and 123 degrees. What is the angle measure? Determine the angle measure is 40 degrees.
Teacher Vocabulary:
  • Protractor
  • Angle
  • Whole number
  • Degree
  • Center
  • Circle
  • Intersect
  • Arc
  • Point
  • Ray
  • One-degree angle
  • Vertex
Knowledge:
Students know:
  • Measurable attributes of geometric shapes, specifically angle size.
  • Units of measurement, specifically one-degree angle (degrees).
  • An angle is measured by the number or iterations of one-degree angles that exactly cover the rotation of the angle.
Skills:
Students are able to:
  • Sketch angles given a specified measure.
  • Use appropriate tools to find angle measure.
Understanding:
Students understand that:
  • the rotation of an angle is measured by the number of one-degree angles that exactly cover the rotation of the angle.
Diverse Learning Needs:
Essential Skills:
Learning Objectives:
M.4.25.1: Define symmetry.
M.4.25.2: Model using a protractor to draw angles.
M.4.25.3: Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
M.4.25.4: Measure the length of an object by selecting and using appropriate tools such as a ruler.
M.4.25.5: Measure length using standard and non-standard units of measurement.
M.4.25.6: Plot points on grids, graphs, and maps using coordinates.
M.4.25.7: Draw points, lines, line segments, and parallel and perpendicular lines, angles, and rays.
M.4.25.8: Identify lines of symmetry on one-dimensional figures.

Prior Knowledge Skills:
  • Build and draw shapes to possess defining attributes.
  • Express the length of an object as a whole number of length units by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps.
  • Compose two-dimensional shapes (rectangles, squares, trapezoids, triangles, half-circles, and quarter-circles).
  • Identify a rectangle.
  • Express the length of an object as a whole number of length units by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps.
  • Define halves, thirds, fourths, quarters, whole, parts (shares) and equal.
  • Distinguish between equal and non-qual parts.
  • Model partitioning circles and rectangles.
  • Decompose pictures made of simple shapes.
  • Identify squares, circles, triangles and rectangles.
  • Explore shapes or figures that can be decomposed into smaller equal parts.

Alabama Alternate Achievement Standards
AAS Standard:
M.AAS.4.24 Recognize and Identify angles in geometric shapes as larger or smaller.


Local/National Standards:

 

Primary Learning Objective(s):

The student will be able to measure angles to the nearest whole number degree using a protractor.

The student will be able to sketch an angle from a specified measure.

Additional Learning Objective(s):

The student will be able to classify angles by its measure.

 Preparation Information 

Total Duration:

61 to 90 Minutes

Materials and Resources:

Class set of protractors

Notebook

Pencil

Worksheet from the website https://www.mathworksheets4kids.com/angles/measuring/standard-type1-easy1.pdf (copy for all students)

Measuring Angles worksheet in the attachment section

Worksheet for Accelerated Students: Make copies as needed

https://www.mathworksheets4kids.com/angles/measuring/multiple-rays1.pdf

Computer, laptop, or iPad (use with intervention website)

Intervention Website: (click on the step by step button)

http://studyjams.scholastic.com/studyjams/jams/math/geometry/measure-angles.htm

Technology Resources Needed:

Desktop computer with access to interactive whiteboard

Worksheet from the website https://www.mathworksheets4kids.com/angles/measuring/standard-type1-easy1.pdf (copy for all students)

Intervention Website: (click on the step by step button)

http://studyjams.scholastic.com/studyjams/jams/math/geometry/measure-angles.htm

Background/Preparation:

Teacher:

The teacher needs to have taught the students how to recognize the different types of angles using pattern blocks. The teacher needs to have enough protractors for all the students. The teacher will need to practice using the protractor tool on the interactive whiteboard. This is an introductory lesson for measuring angles.

Student:

The student should know the parts of an angle. The student needs to know the following terms: vertex, rays, acute, obtuse, right, and straight.

  Procedures/Activities: 

Before:

  1. Write on the interactive whiteboard the following: Angle, Acute Angle, Obtuse Angle, and Right Angle.
  2. The teacher will ask the students to stand by their desk and model each term with their arms. The teacher will model first.
    1. Angle – the arms will make a V.
    2. Right Angle – the arms will make an L.
    3. Acute Angle – the arms will make a V.
    4. Obtuse Angle – the arms will make a wide V.
    5. The teacher will mix up the terms and repeat.

During:

  1. The teacher will hold up a protractor and tell the students that this is the instrument to measure an angle. The teacher will pass out the protractors. The protractor has two rows of numbers from 0 to 180.
  2. The teacher will explain the parts of the protractor.
    1. The hole in the middle of the ruler part is for the point (vertex) of the angle.
    2. The numbers from 0 to 180 on top are for the angle with the opening on the left (>).
    3. The numbers from 0 to 180 on the bottom are for the angle with the opening on the right (<).
    4. The teacher will tell the students to draw an angle with the opening on the left (>). Model this on the interactive whiteboard.
    5. The teacher will show the students how to place the vertex in the right place and line up the 0 on the left side of the protractor.
    6. The teacher will then follow the other leg (ray) of the angle to show the measure on the protractor. The teacher will write the number and then show the students that the small 0 at the top of the number is the symbol for degrees.
    7. The teacher will tell the students that if the legs (rays) are not long enough, then they can extend the legs with the ruler part of the protractor.
    8. The teacher will tell the students to draw an angle that opens to the right (<). The teacher will show the students how to use the numbers on the bottom.
    9. The teacher will do a guided practice with the worksheet called https://www.mathworksheets4kids.com/angles/measuring/standard-type1-easy1.pdf. The students can work with partners. The teacher will monitor engagement and do an informal assessment. The intervention will be to do one-on-one differentiated instruction. 

After:

  1. The teacher will hand out the formal assessment called Measuring Angles in the attachment section. The accelerated students will be assigned the worksheet, https://www.mathworksheets4kids.com/angles/measuring/multiple-rays1.pdf.


Attachments:
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  Assessment  

Assessment Strategies

Informal:

The teacher will monitor the students as they measure angles in the group activity, making sure that all students are measuring the angles accurately with the protractors.

Formal:

The teacher will use the worksheet called Measuring Angles in the attachment section to make sure all students have mastered measuring angles with a protractor.  

Acceleration:

The accelerated students will be assigned the worksheet, https://www.mathworksheets4kids.com/angles/measuring/multiple-rays1.pdf.

Intervention:

Struggling students may need one-on-one instruction in a small group and use the following website: (click on the step by step button) http://studyjams.scholastic.com/studyjams/jams/math/geometry/measure-angles.htm.


View the Special Education resources for instructional guidance in providing modifications and adaptations for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.