### Understanding Radius Trimming in AutoCAD
Trimming a radius in AutoCAD involves modifying curves or arcs without leaving unwanted segments. This guide outlines effective steps to achieve this using various commands and techniques available in AutoCAD 2025.
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### Step-by-Step Guide to Trim a Radius
1. **Accessing the Fillet Command**
Start by navigating to the **Home** tab on the ribbon. Locate the **Modify** panel and click on the **Fillet** drop-down menu. From the options presented, select **Fillet** to activate the command.
2. **Setting the Fillet Radius**
Once the Fillet command is active, the command prompt will prompt you to enter the radius. Type `r` followed by hitting **Enter**. Here, you will specify the new fillet radius you intend to use.
3. **Defining Target Lines**
After setting the radius, click on the first line you wish to modify. Subsequently, select the second line. AutoCAD will then create an arc based on the radius you specified, effectively trimming the previous corners.
4. **Completing the Command**
If necessary, you can continue to select more objects or press **Enter** to finalize the command. The result should showcase a clean arc, seamlessly blending with the selected lines.
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### Additional Techniques for Radius Modifications
#### Changing a Radius on Existing Arcs
1. **Selecting the Arc**
Click on the **Annotate** tab. From the **Dimensions** panel, choose **Dimension**. Select the arc or circle where you want to modify the radius.
2. **Prompt for Dimension Type**
You will get a prompt asking whether you want to measure the radius or the diameter. Type `r` for Radius or `d` for Diameter depending on your requirement.
3. **Placing the Dimension**
Before concluding, adjust the text positioning if needed and click to place the dimension line effectively in your drawing.
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### Trimming Existing Radii
To remove or alter existing radius features in AutoCAD:
1. **Utilizing the Trim Command**
Navigate to the **Home** tab, and in the **Modify** panel, select the **Trim** option. You can also use the shortcut by typing `TR` in the command line.
2. **Choosing Cutting Objects**
Select the objects that will act as cutting edges. After defining your cutting limits, press **Enter**.
3. **Trimming Unwanted Segments**
Click on the radius segment you wish to remove. AutoCAD should eliminate the portion of the radius that intersects with a cutting edge, streamlining the design.
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### FAQs
**What is the difference between a fillet and a trim in AutoCAD?**
Fillet creates a rounded corner between two intersecting lines, whereas trim removes parts of lines that exceed a defined boundary set by other objects.
**How can I reset the fillet radius to zero?**
When using the fillet command, you can type `0` when prompted for a radius. This action will eliminate the arc and extend the lines until they intersect.
**Can I undo a trim operation in AutoCAD?**
Yes, you can reverse a trim operation by using the **Undo** command, which can be accessed by pressing `Ctrl + Z` or by typing `U` in the command line.
