Autodesk 00308-011408-9F30A - VLA AUTOSKETCH R8-MEDIA W9X/NT, User Manual, Page: 173 / 400

Drawing Ellipses
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Drawing Ellipses
An ellipse is a closed symmetrical curve that resembles a flattened circle.
Mathematically, the path of a point that moves so the sum of the distances
from it to a pair of fixed points remains constant. You might use an ellipse to
illustrate the path of a planet in a drawing of the solar system, or to accu-
rately convey the appearance of a bolt hole in an isometric drawing.
AutoSketch provides two commands that allow you to draw ellipses. Ellipse
Rectangle creates an ellipse using two points to define a bounding rectangle
for the ellipse. Ellipse Axes allows you to create an ellipse by specifying the
major and minor axes using three points. This command also lets you create
a slanted ellipse using the third point to determine slant for the ellipse.
An elliptical arc is an ellipse with less than 360 degrees. It is defined by a
centerpoint, major axis, minor axis, starting angle, and included angle. It
might be used to illustrate an isometric view of a circular arc.
To draw an ellipse that fills a rectangle
1 On the Draw menu, click Circle, Ellipse Rectangle, or click the Ellipse
Rectangle button on the All-In-One toolbar.
2 Click a point that defines a corner of the rectangle. A rubber-band
rectangle follows the movement of the pointer.
3 Click a point that defines the opposite corner of the rectangle. AutoSketch
draws an ellipse tangent to all four sides of this rectangle.
NOTE
If you are using an isometric reference grid, you can align the ellipse
to the grid by clicking the Align to Grid button on the edit bar before entering
the first point.