# Polyline
The polyline labeling tool allows you to draw a line on an image.
{% hint style="info" %}
The Polyline tool is supported across the Image, Video, DICOM, and Medical labeling editors.
{% endhint %}
## The Polygon Labeling Tool in Ango Hub
### How to add a Polyline tool to your project
From the project’s *Settings* tab, enter the *Label Set* section.
Click on *Add Category*. From the list that appears, click on *Polygon*.
A new row will appear named *Polyline*. Click on it to expand it.
Give your polyline tool a title and description.
Enable the *Required* toggle if you want to force labelers to create a polyline on every asset. When the toggle is disabled, labelers will be able to save and move to the next asset without creating a polyline label using this class.
If you would like to ask labelers further questions, for example, if you want to show a further *radio* after drawing the polyline, click on *Add Classification* and add a further question. More[ on nested questions here](https://docs.imerit.net/labeling/labeling-tools/tools/nested-classifications).
### How to Draw a Polyline
Click on the image where you’d like the first point of the polyline to be. Click again where you’d like the second point to be, and so on. When you are done, click on the first point again or press on *N* on your keyboard to close the polygon.
While drawing, you may click anywhere with the right mouse button to delete the last point you have placed.
To edit a polyline's points, select it by clicking on it, then drag the polyline itself or one of its points.
## Edge Sharing
While drawing a polyline, if you press E, Hub will highlight the points of other polygons, polylines, and points. By clicking on the other object's points, you can snap your current polyline's points to them:
By snapping at least two points to the existing polygon and holding Alt (⌥ on macOS) + clicking, you can quickly anchor a series of points to the existing object, as shown in the GIF above.
