Autodesk 00308-011408-9F30A User Guide - Page 173

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 accurately 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. Drawing Ellipses | 163