## Measure Angles with a Protractor

#### Aligned To Common Core Standard:

**Grade 4 Geometry** - 4.MD.6

How to use a Protractor - Measuring angles can be difficult, especially when you are using a protractor. When you measure the angles, you must believe that angles are parts of a circle. By knowing this, you can learn how the design of the protractor works. Now, take a look at these steps, by which you can calculate the angle with ease. - To measure an angle, you firstly need to place the protractor on the dot of the line you want to find the angle of. - The one edge of the line should be on the center of the protractor, while the other edge should tell you the angle. - Notice that the protractor shows two numbers on each line. Each number for either the left or the right corner of the protractor. The numbers will tell you the degree of the edge of the line on the opposite end. - Now, you just mark the point of the angle, and you're good to go. If you want to know how you should place the protractor of the figure, just point the center dot of the protractor at the point of the angle and align the bottom line (on the protractor) with one of the lines. These worksheets will help students learn to use Protractors to measure angles.

### Printable Worksheets And Lessons

- Protractors Step-by-Step
Lesson- I walk you through lining it up and determining the
angle. I would first go over which scale marking to use with your
students.

- Guided Lesson
- This one does not measure angles, it labels them (acute, right,
obtuse).

- Guided Lesson Explanation
- Each problem gets its own page. Sorry, if you are printing them
out for all the kids.

- Classifying
and Measuring Angles 5-Pack - Classifying angles for the first
time.

- Practice Worksheet
- Break out the protractors and get to work!

- Classify and Measure
Angles Five-Worksheet Pack - It doesn't say it, but we need
to know if it is acute, obtuse, right, or straight.

- Matching Worksheet
- Match the angles and its measurement.

#### Homework Sheets

We give you the protractor. It really helps to do a few of these as a class.

- Homework 1 - A protractor is used to measure angles. We will consider the use of a protractor that has the shape of a semi-circle and two scales marked from 0° to 180° in both directions.
- Homework 2 - Since we need to start counting from zero (where the line is even) we use the top scale to determine the measure of the angle.
- Homework 3 - Acute angles measure less than 90°, but more than 0°.

#### Practice Worksheets

Each sheet has a different purpose. Classifying angles and measuring angles are what we focus on here.

- Classify Practice 1 - A right angles measure exactly 90°.
- Measure Practice 2 - An obtuse angles measure more than 90°, but less than 180°.
- Practice 3 - One ray is already lined up with 0° on the inside ring, which is the same as 180° on the outside ring. Read the angle measurement on the inner ring where the other ray crosses the protractor.

#### Math Skill Quizzes

The printed protractors are a bit in your face here.

- Quiz 1 - Is this angle acute, right, or obtuse?
- Quiz 2 - Put your skills to use for you now.
- Quiz 3 - Can I be of use to you?

**What Professions Use Protractors?** -
Protractor is one of the most basic pieces of geometric equipment in the world. It is introduced to us at a very early age and stays with us throughout the majority of professional life. Several professions all over the world make use of the protractor extensively. Some of which are:
**Cartographers and Photogrammetrists:** These professionals collect, interpret, and analyze geographic information, using aerial photographs and satellite data.
**Architects:** They create detailed drawings of all the buildings that are not yet built. Protractors are always an important tool for an architect.
**Civil Engineers:** These professionals prepare topographical and relief maps and prepare drawing on their projects such as highways, pipelines, flood control projects, and bridges, etc.
**Aerospace Engineers:** They are responsible for installing operating and integrating simulators, consoles, and other instruments on the space shuttle. Placing everything at their right position and angle is always a must
**Mapping Technicians:** Thee technicians gather information for several topographical purposes and verify that information using geometric means and tools.