Guide
Desmos Geometry Tool: Points and Lines
Introduction to using the free Desmos Geometry Tool to create lines and points.
Desmos Geometry Tool: Points and lines
The first two posts in the Math Shapes series featured hands-on activities to build shape concepts. The Math shapes: Marshmallows and toothpicks activities post introduced tracing shapes and creating simple shapes using marshmallows and toothpicks. The Math shapes: Classifying and drawing shapes discussed organizing common shapes by classifications: polygons, triangles and quadrilaterals and then typical tools used by BLV students to create and/or draw the shapes. A future post in this series will include using the Desmos Geometry Tool to create accessible math shapes. However, before creating these shapes using the Desmos Geometry Tool, teachers should first learn the basics about this tool, then learn how to use the tool with JAWS. This post, will introduce how teachers/students with vision can create and access digital points and different types of lines using the Desmos Geometry Tool.
Introduction to the Desmos Geometry Tool for sighted teachers
Note: There will be future posts about using the Desmos Geometry Tool with JAWS. Since many TSVIs and math teachers are sighted, we’ll start by introducing the basics of the Desmos Geometry Tool without JAWS.
Desmos is a free mainstream graphic-based math tool that is embedded into most math classes, online textbooks and assessments – including high stakes assessments. Most educators and students are familiar with and use the fully accessible online Desmos Graphing Calculator. Desmos recently released the NEW Desmos Geometry Tool, a powerful and interactive workspace that allows users to visualize and explore plane geometry through construction, measurement, transformations and more.
This first video is a quick 3-minute introduction of what the Desmos Geometry Tool can do.
Getting started with the New Desmos Geometry Tool YouTube video by Desmos
To find the Desmos Geometry Tool
Go to Desmos.com and select the Geometry button or go directly to desmos.com/geometry.
Create a free account and log in. You must be logged in to save or share your creations!
Basic layout of the Desmos Geometry Tool
The content in this post uses the Desmos website on a computer.
The basic layout of the Desmos Geometry Tool is similar to the other Desmos tools. The screen is divided into 1/3 on the left and 2/3rds on the right. Both sides have a tool bar located above that is related to that section. The left side contains the Expression List (sometimes called the Expression Box). The right 2/3rds area is a blank canvas where points, lines and shapes can be created.
This post is an introduction on how to create points and different types of lines using the tool bar above the canvas, without a screen reader.
Buttons in the tool bar
The tool bar is centered directly above the canvas. Once a tool button is selected, that feature is active until another tool button is selected. Typically users will exit the current mode by clicking on the Select tool button. In this post, the focus will be on the Select tool button, the Point tool button and the Line tool button, along with the Styles and Settings options.
- Select tool button (arrow symbol): Once items are added to the canvas, such as movable points, lines, circles or angles, you can move or change these items on the canvas.
- To change the length of a line, click on the Select tool button, then click the desired point of the line segment and move that point to a new location and click.
- Any segment that relies on that point will also adjust.
- Clicking on the Select tool button will disable the previously selected tool that adds a point, line, circle or polygon.
- Point tool button: Add a point or midpoint on the canvas.
- To create a point: Select the Point tool options, then select Point. On the canvas, click to create a point.To create multiple points after the first point is created: Click multiple times in the desired locations. To stop adding points, click on another tool button. Example: Click on the Select tool button.Once the points are created on the canvas, click on the point and the tool bar options change to: Delete, hide, transform the point or Style options (three dots icon). The Style options are Color, Label (default is the letter “A,” but you can type in any character or word) and Draggable (default is draggable. Check or unchecked to toggled on or off).
- Midpoint: After creating a line segment, use the Midpoint option under the Point tool button to automatically add a point in the middle of that line segment.
- Line tool button: Options are Segment, Line, Ray, Vector, Parallel and Perpendicular. Note: In the Desmos geometry tool, the “Segment” is a line with two end points. “Line” is similar to a Segment (has two points) but the Line is unending. A “Ray” has a point that ends and a point that is unending. A “Vector” is similar to a Ray with an ending point but the second point is an arrow (with a specific ending point).
- To make a line segment on the canvas, click on the Line tool button options, then select Segment. In the canvas, click on a previously created point or click anywhere to create a new point. Move the cursor to another existing point or move to a desired location, then click again to set the end of the line segment.
- Parallel: This tool creates a parallel line from an existing line. Note: The original can be any type of line (segment, ray, line, vector) but the newly created parallel line will be a “line”.
- Select the Line tool, then select Parallel. On the canvas, select the desired line (it will duplicate the line) then move the new line to the desired location.
- Perpendicular: Is the same as creating a parallel line.
- Parallel: This tool creates a parallel line from an existing line. Note: The original can be any type of line (segment, ray, line, vector) but the newly created parallel line will be a “line”.
- Style tool button: Users can customize the color of the lines, text and points.
- Select an item on the canvas and the tool bar options change. Select the three dots to open the Style tool options. Selected the desired customized color option. Note: The default lines are blue, and the default points are grey.
- Click the back arrow to exit the style tool menu.
- To delete
- To delete everything within a chosen area, click on the Select tool button drop down, then the Box Select option. On the canvas, click on the top left corner and drag down and to the right which creates a selected area (grey box). Then select the trash can in the tool bar. This will delete everything within that selected box.
- To delete the last item added to the canvas, select the Undo button located above the Expression Box (left 1/3 column).
Settings button
The settings button (wrench icon) is located at the far right of the tool bar. Select the grid and the options include:
- Small font A and large font A options: Default is A with small font. Select the large A to magnify.
- Reverse contrast: Default is unselected.
- Lock viewport: Does not allow the user to drag items around the screen.
- Grid: Use the slider button to turn the blank canvas background into a grid with major and minor grid lines.
- The minor grid box is checked by default. Unchecking the minor grid box causes those minor lines to disappear so canvas now has only larger boxes.
- The Axis converts the grid into a coordinate plane with axis. The axis numbers will show by default but can be turned off by unchecking the Axis Numbers box. There is also an arrow checkbox (default is unchecked) that will add arrows to the coordinate plane lines.
- Braille Mode: To be discussed in a later post
- Radians:
- Degrees buttons:
This is an excellent 13:31 minute video that demonstrates all of things discussed in this post.
Using the NEW Desmos Geometry Tool (part 1) by Andy Malbouef, Media4Math:
Resources
More posts in this geometry series!
- Math shapes: Marshmallows and toothpicks activity!
- Math shapes: Classification and drawing of shapes
- Math shapes: Introducing APH Memory Puzzles
- Desmos Geometry Tool: Points and lines
- Desmos Geometry Tool: Circles and polygons
- Creating an accessible geometry worksheet: Desmos Geometry Tool (workflow)
- More Desmos Geometry Tool posts! (Coming soon!)
By Diane Brauner
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