Feature Description

An arc can be defined through parameters like center point, endpoints, start point, radius, and angle. Multiple methods are available for creating circular arcs or elliptical arcs. The application provides three common approaches: circular arc, three-point arc, and elliptical arc.

Feature Entry

• Features Tab->Feature Drawing Group->Line Drop-down List->Arc.

Steps

Drawing an Arc by Specifying Three Points (Triple-Point Arc)

1. With the current layer editable, in the Features tab's Feature Drawing group, click the Line drop-down button and select Triple-Point Arc. The triple-point arc cursor will appear.
2. Move the mouse to the map. The coordinate values will display in real-time in the parameter box as the mouse moves. Enter coordinates for the first point in the parameter box (use Tab to switch between input fields) and press Enter to confirm the starting position.
3. Move the mouse again, input coordinates for the second point in the parameter box, and press Enter to confirm.
4. Continue moving the mouse, input coordinates for the final point, then press Enter to complete the arc.
5. Right-click to cancel the current operation.

Drawing an Arc by Specifying Start Point, Center, and Angle (Circular Arc)

1. In the Features tab's Feature Drawing group, click the Line drop-down button and select Circular Arc. The circular arc cursor will appear.
2. Move the mouse to the map. Enter the center point coordinates in the parameter box (use Tab to switch fields) and press Enter to confirm.
3. Move the mouse again, input the radius value in the parameter box, then press Enter to draw a circle.
4. Using the circle as reference, move the mouse and input the start angle (angle between positive X-axis and arc's starting radius counterclockwise) to determine the arc's starting position.
5. After setting the start angle, continue moving the mouse and input the sweep angle in the parameter box. Press Enter to complete the arc.

Drawing an Elliptical Arc

1. With the current layer editable, in the Features tab's Feature Drawing group, click the Line drop-down button and select Ellipse Arc. The elliptical arc cursor will appear.
2. Move the mouse and input coordinates for the starting point of a semi-axis (major or minor) in the parameter box (use Tab to switch fields). Press Enter to confirm.
3. Move the mouse again. The system displays real-time length and angle relative to the positive X-axis. Input these values in the parameter box and press Enter to complete the semi-axis.
4. Continue moving the mouse, input the length of the other semi-axis, then press Enter to complete the ellipse.
5. Move the mouse and input the start angle (angle between positive X-axis and arc's starting radius counterclockwise) to determine the elliptical arc's starting position.
6. Continue moving the mouse, input the sweep angle in the parameter box, then press Enter to complete the elliptical arc.