Creating Dimensions
Creating dimensions involves two basic steps: selecting the objects to be measured, and locating the dimension. By default the magnitude of the dimension is calculated automatically and is recorded as the dimension text, measured in current World units. (Leader dimensions, which contain text labels, are the exception to this rule.) You can override the default text of a dimension by specifying the text in the Inspector Bar prior to finishing the dimension.
You can also change the dimension text in the dimension's Properties, by changing the Attributes field of the General page.
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Note: To create several types of dimensions automatically in one step, see see Auto Dimension.
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When Auto Add Constraints is active, any dimensions you assign are created as variables that appear in the Calculator Palette. 
Dimension variables can be constrained to other dimensions, or to other variables or numbers. This is particularly powerful when used in conjunction with Auto Constraints. See See Constraining Dimensions.
Orthogonal Dimension
Creates a horizontal or vertical dimension.
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Note: To create orthogonal dimensions automatically, see Auto Dimension.
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- Select the first point.
- Select the second point, or enter the length and angle of the dimensioned line in the Inspector Bar.
- For a horizontal dimension, move the mouse above or below the two points and click to define the location. You can also enter the length of the witness lines in the Inspector Bar.
- For a vertical dimension, define the dimension at either side of the two points.
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Note: To create parallel dimensions automatically, see see Auto Dimension.
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- Select the first point.
- Select the second point, or enter the length and angle of the dimensioned line in the Inspector Bar.
- Move the mouse and click to define the location. You can also enter the length of the witness lines in the Inspector Bar.
For any two endpoints, the absolute length is parallel to the line between the points. 
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Note: To create distance dimensions automatically, see see Auto Dimension.
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- Select the two lines, or select them by snapping to either of their endpoints.
- Place the dimension, and the lines are made parallel.
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Note:Because Auto Add Constraints is on, the Distance dimension appears as a variable in the Calculator Palette and can be edited. See Constraining Dimensions.
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Rotated Dimension
Creates a dimension projected in a specified direction.
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Note: To create angular dimensions automatically, see see Auto Dimension.
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Angle Between Two Lines
- Select the two lines.
- Move the mouse to dimension the acute or obtuse angle. Click to locate the dimension, or enter the length and angle in the Inspector Bar.
Be careful where you select the lines. If you select close to the angle vertex, you could dimension the complementary angle. 
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Note: To create radius or diameter dimensions automatically, see see Auto Dimension.
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- Select the arc or circle.
- Move the mouse and click to locate the dimension, or enter the length and angle in the Inspector Bar.
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There is a special tool for dimensioning walls created via the Architecture tools. See Wall Dimension.