Several  Several types of construction lines and circles are available.

Construction-Angular Line

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1. Select a point through which the construction line will pass. Select a second point, or enter the slant in the Inspector Bar.
   
2. The construction line is created, with the properties assigned to the construction layer.
   

 Construction-Horizontal Line, Vertical Line

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1. Select the point through which the construction line will pass.
2. Continue creating construction lines of the same type, and select Finish when done.
   

Construction-Parallel

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1. Select the line to which the construction line will be parallel. You can also select a construction line.
   
2. Select a point through which the construction line will pass, or enter the offset in the Inspector Bar.
   
   

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   Tip: To make multiple construction lines separated by the same distance, lock the Offset field in the Inspector Bar, and create parallel lines from each successive line.

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Construction-Perpendicular

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1. Select the line to which the construction line will be perpendicular. You can also select a construction line.
   
2. Select a point through which the construction line will pass.
   

 Construction-Center and Point Circle

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Creates a construction circle by defining its center and a point on its circumference.

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Construction-Double Point Circle

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Creates a construction circle by defining two opposite points on its circumference.

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Construction-Triple Point Circle

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Creates a construction circle that passes through three points.

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 Construction-Perpendicular by Line

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Creates a construction line perpendicular to a line defined by two points.
Start with two circles, We will create a construction line halfway between the centers of the two circles perpendicular to the axis between the two centers.

1. Select the tool, then snap to the center of the first circle.
   
2. Move the cursor. Notice that the preview of the construction line is parallel to the line you are dragging out.
   
3. Snap to the center of the other circle to set the construction line.
   

Construction-Bisection

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Creates a construction line which bisects an angle

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