# Measure Angles with a Protractor Worksheets

Having the ability to understand how two structures are orientated in relational form to one another is paramount to understanding how to construct solid and time lasting structure. Even ancient civilizations that understood this. Being able to create those structures were heavily dependent on their use of angle measures. Ultimately the measure of how two lines come together forms an amazement of different geometric shapes. They help us make the transition from two-dimensional to the three-dimensional world. Protractors are tools that can be used to determine an almost exact relationship between the meeting of two lines. These worksheets will help students learn to use Protractors to measure angles.

### Aligned Standard: Grade 4 Measurement & Data - 4.MD.6

- 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.

- Answer Keys - These are for all the unlocked materials above.

### 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?

### How to use a Protractor

Measuring angles can be difficult, especially when you are using a protractor. When you measure the angles, you must understand that angles are portions 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 with the help of a protractor.

**Step 1 - Line up the Vertex at Center Mark of Protractor**

To measure an angle, you firstly need to place the protractor on the vertex of the angle. This is the exact point where the two lines meet. You will place this vertex in the center mark of the protractor. This should be a clear whole that is actually punched through the frame. The edge of the bottom line should be on the centered on this line. It should directly go over that bottom line that runs the extent of the bottom of the protractor. That bottom line is called the Zero edge.

**Step 2 - Read the Measures**

We will look at the other line that is touching the zero edge and see if that were extended infinitely would touch on the protractor scale. Notice that the protractor shows two numbers on two different scales. In one direction it read 0 ° to 180 ° and the same in the opposite direction. These numbers will tell you about the measure in degrees of the edge of the line on the opposite end. You will need to use your classification of angles understand which scale is proper for your measure. If the measure is obtuse, the scale must be greater than 90 °. If the measure is acute, the scale must be less than 90 °.

Remember that it may help to extend either of those lines to take better readings. You can extend those lines at any time with a straight edge. 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.

## What Professions Use Protractors?

A 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.