# Creating an arc based on an azimuth and endpoint

The Arc (Azimuth and End Point) function creates an arc, which can be used as part of a more complex polygon geometry. For aeronautical purposes, this function creates an AF leg according to ARINC Specification 424.

Note:

The radius is calculated using the distance between the endpoint and the centerpoint; there is no separate parameter for the radius in the function.

Steps:
1. Start ArcMap.
2. On the menu bar, click Customize > Toolbars > Production Feature Builder.
3. Click the Launch Feature Builder button on the Production Feature Builder toolbar.

The Feature Builder window appears in ArcMap.

 The Feature Builder window

Tip:

The Feature Builder window can be placed anywhere in ArcMap, or in the TOC, with the aid of the arrows showing the possible placement positions.

4. Choose Arc (Azimuth and End Point) in the list on the Functions tab.

5. Define a coordinate for the start point of the polyline by doing one of the following:
• Clicking the Pinprick button on the Production Feature Builder toolbar, then clicking on the map
• Typing the coordinates in the cells on the Input tab in the Coordinates area
Tip:

To view the input coordinates on the map, double-click the row headers for each coordinate.

6. Repeat step 5 to define a coordinate for the endpoint of the geodesic arc.
7. Click the cell next to From Azimuth and type a value for the starting azimuth.

The from azimuth is the arc's starting azimuth relative to the centerpoint. Azimuth values are measured from north (0°). The default units is degrees.

Tip:

You can right-click the parameter name and change the unit of measurement. If you change the unit of measurement after defining a value, the value is converted to the new unit of measurement, and you may need to redefine the value.

8. If necessary, click the drop-down arrow next to Clockwise and choose False.

This indicates whether or not the arc is created in a clockwise direction. There are two options:

• True—The arc is created in a clockwise direction based on the first input coordinate and the From Azimuth.
• False—The arc is created in a counterclockwise direction based on the first input coordinate and the From Azimuth.
9. If necessary, click the cell next to MagVar Value and type a value for the magnetic variation.

This can be a specified value or from a field defined in the MagVar Source parameter. The default unit is degrees.

10. Tip:

You can right-click the parameter name and change the unit of measurement. If you change the unit of measurement after defining a value, the value is converted to the new unit of measurement, and you may need to redefine the value.

11. If necessary, click the drop-down arrow next to MagVar Source and choose a source for the magnetic variation.

This is the source of the magnetic variation value.

12. If necessary, click the drop-down arrow next to MagVar Year and choose a different year for the World Magnetic Model.

This is the year associated with the magnetic variation value.

13. Click the Execute button .

An arc is created between the azimuth and endpoint.

Tip:

If the arc does not appear, click the Add Scratch Data Layers button at the top of the Feature Builder window.

6/14/2012