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 MA2015 (2016) Grade: 4 24 ) Measure angles in whole-number degrees using a protractor. Sketch angles of specified measure. [4-MD6]

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:

Technology Resources Needed:

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:

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

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.
The teacher will explain the parts of the protractor.
The hole in the middle of the ruler part is for the point (vertex) of the angle.
The numbers from 0 to 180 on top are for the angle with the opening on the left (>).
The numbers from 0 to 180 on the bottom are for the angle with the opening on the right (<).
The teacher will tell the students to draw an angle with the opening on the left (>). Model this on the interactive whiteboard.
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.
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.
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.
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.
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:

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: **Some files will display in a new window. Others will prompt you to download.

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:

Intervention:

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.