Autodesk 057B1-41A111-1001 - AutoCAD LT 2010, Руководство пользователя

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Use the 3D UCS icon to help you visualize which plane these coordinates will
be projected on; the 3D UCS icon does not use a broken pencil icon.
Enter Coordinates to Specify Points
When a command prompts you for a point, you can use the pointing device
to specify a point, or you can enter a coordinate value at the command prompt.
Overview of Coordinate Entry
You can enter two-dimensional coordinates as either Cartesian (X,Y) or polar
coordinates. When dynamic input is on, you can enter coordinate values in
tooltips near the cursor.
Cartesian and Polar Coordinates
A Cartesian coordinate system has three axes, X, Y, and Z. When you enter
coordinate values, you indicate a point's distance (in units) and its direction
(+ or -) along the X, Y, and Z axes relative to the coordinate system origin
(0,0,0).
In 2D, you specify points on the XY plane, also called the work plane. The
work plane is similar to a flat sheet of grid paper. The X value of a Cartesian
coordinate specifies horizontal distance, and the Y value specifies vertical
distance. The origin point (0,0) indicates where the two axes intersect.
Polar coordinates use a distance and an angle to locate a point. With both
Cartesian and polar coordinates, you can enter absolute coordinates based on
the origin (0,0), or relative coordinates based on the last point specified.
Another method of entering a relative coordinate is by moving the cursor to
specify a direction and then entering a distance directly. This method is called
direct distance entry.
You can enter coordinates in scientific, decimal, engineering, architectural,
or fractional notation. You can enter angles in grads, radians, surveyor's units,
or degrees, minutes, and seconds. The UNITS command controls unit format.
See also:
Enter Cartesian Coordinates (page 135)
Enter Polar Coordinates (page 137)
134 | Chapter 6 Create and Modify Objects