Create and modify 3D models > Create 2D geometry > Draw construction circles
  
Draw construction circles
You can create construction circles with the Center & Radius, 3 Points, Tangent & Center, and other commands.
The following commands will get you started; follow the instructions on the status bar to use other commands.
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When you draw construction lines and circles, with 2D CoPilot support, the cursor snaps to the existing elements in the viewport and you can use 2D CoPilot features such as Measure Relative. All construction line commands are supported by the 2D CoPilot. The following construction circle commands are supported by the 2D CoPilot:
• Center & Radius
• 3 Points
• Tangent & Center
To create a 2D construction circle,
1. Click Modeling and then, in the Draw group, click the arrow next to (Construction Circle).
2. Click Center & Radius.
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To change from the radius mode to the diameter mode,
• Click on the status bar, or,
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When you change from the radius mode to the diameter mode , the following circle commands change:
• On the Modeling tab, in the Draw group, the Construction Circle Center & Radius changes to Center & Diameter.
• On the Modeling tab, in the Draw group, the Circle Center & Radius changes to Center & Diameter.
• On the Modeling tab, in the Modify 2D group, Radius changes to Diameter.
3. Click a point in the workplane for the center location of the circle.
4. Move the cursor to see the visual feedback (radius of the circle).
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In the diameter mode, the visual feedback shows the diameter of the circle. To switch to diameter mode, see Change 2D CoPilot settings.
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• To set the radius of a circle in the radius mode, press SPACEBAR, click on the Option Mini Toolbar (OMT), and type a value for the radius. You can also right-click somewhere in the viewport, choose Set Radius from the context menu, and type a value for the radius.
• To set the diameter of a circle in the diameter mode, press SPACEBAR, click on the Option Mini Toolbar (OMT), and type a value for the diameter. You can also right-click somewhere in the viewport, choose Set Diameter from the context menu, and type a value for the diameter.
5. Click a point in the workplane for the end location of the circle. You can also type the desired radius and press ENTER.
6. Create additional circles, if required.
7. Click to complete the operation.
To create a 2D construction circle using 3 points,
1. Click Modeling and then, in the Draw group, click the arrow next to (Construction Circle).
2. Click 3 Points.
3. Select the first point of the circle. If you select a point on an existing geometrical element (except a center point, midpoint, vertex, or an intersection point), the circle is drawn tangentially to that element.
4. Move the cursor to increase the radius of the circle.
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• As you move the cursor over other 2D elements in the viewport, the 2D CoPilot automatically shows points on the elements where the circle is tangent to those elements.
• In the diameter mode, the visual feedback shows the diameter of the circle. To change to the diameter mode, see Change 2D CoPilot settings.
5. Select the second point of the circle. If you select a point on an existing geometrical element (except a center point, midpoint, vertex, or an intersection point), the circle is drawn tangentially to that element.
6. Select the third point of the circle to complete the circle. You can select a point on an existing geometrical element (except a center point, midpoint, vertex, or an intersection point) to create the circle tangentially to that element. You can also type the radius and press ENTER.
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When you select the third point of the circle:
• To set the radius of a circle in the radius mode, press SPACEBAR, click on the Option Mini Toolbar (OMT), and type a value for the radius. You can also right-click somewhere in the viewport, choose Set Radius from the context menu, and type a value for the radius.
• To set the diameter of a circle in the diameter mode, press SPACEBAR, click on the Option Mini Toolbar (OMT), and type a value for the diameter. You can also right-click somewhere in the viewport, choose Set Diameter from the context menu, and type a value for the diameter.
7. Create additional circles, if required.
8. Click to complete the operation.
To create a 2D construction circle using Tangent and Center,
1. Click Modeling and then, in the Draw group, click the arrow next to (Construction Circle).
2. Click Tangent & Center.
3. Select the first point of the circle. If you select a point on an existing geometrical element (except a center point, midpoint, vertex, or an intersection point), the circle starts tangential to that element.
4. Move the cursor to increase the radius of the circle.
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• As you move the cursor over other 2D elements in the viewport, the 2D CoPilot automatically shows points on the elements where the circle is tangent to those elements.
• In the diameter mode, the visual feedback shows the diameter of the circle. To change to the diameter mode, see Change 2D CoPilot settings.
5. Select the second point of the circle to complete the circle.
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When you select the second point of the circle:
• To set the radius of a circle in the radius mode, press SPACEBAR, click on the Option Mini Toolbar (OMT), and type a value for the radius. You can also right-click somewhere in the viewport, choose Set Radius from the context menu, and type a value for the radius.
• To set the diameter of a circle in the diameter mode, press SPACEBAR, click on the Option Mini Toolbar (OMT), and type a value for the diameter. You can also right-click somewhere in the viewport, choose Set Diameter from the context menu, and type a value for the diameter.
6. Create additional circles, if required.
7. Click to complete the operation.
To create a 2D concentric construction circle,
1. Click Modeling and then, in the Draw group, click the arrow next to (Construction Circle).
2. Click Concentric.
3. Select an existing circle in the viewport.
4. Move the cursor to increase the radius of the circle.
5. Select a point in the viewport to complete the circle. You can also type the radius and press ENTER.
6. Create additional circles, if required.
7. Click to complete the operation.
To create a 2D construction circle using diameter mode,
1. Click Modeling and then, in the Draw group, click the arrow next to (Construction Circle).
2. Click Diameter.
3. Select the first point (first diameter position) of the circle in the viewport.
4. Move the cursor to increase the radius of the circle.
5. Select the second point (second diameter position) in the viewport to complete the circle.
6. Create additional circles, if required.
7. Click to complete the operation.