Cadastral Tools

Internal Angles Tool

The internal angle is the smaller angle between two lines meeting at a common point. The tool calculates internal angles both within a plan and between plans for any number of selected lines. Overlying plans with different basis of bearing will have different recorded bearings for the same line. Comparisons using internal angles is a quick way to find actual differences. Read more...

Basic Use

You must have at least two connected lines selected. You can select multiple groups of 2 or more connected lines.

1. click to start the tool
2. Select the desired lines.
3. Ctrl+Shift+ click to calculate

Results are shown in the Tool Results window, and graphics on the map.

Keep it simple! Complex fabrics can have many overlying lines. Use the Fabric controls to show only the plan or plans needed.

Selecting Lines

Selecting lines can be difficult in complex situations. Consider the following:

• Order of selections is unimportant.
• For complex areas, first review the lines under a point using the Identify Tool

Selection Operations

1. click on a line to start, or use a selection box to select several lines at once.
2. Shift+ click to add another line
3. Ctrl+ click to remove a line from the selection
4. if you want to add a shorter line under the selected lines, Shift+ click over a section of line.
5. Remove lines you don't want from the first selection using Ctrl+ click on a collinear segment that does not contain the desired lines.
6. you can use a selection box (click and drag), with Ctrl and Shift combinations.

Tip! This tool requires selection of lines from the fabric lines layer shown on the map. If your site does not use views with a lines layers as part of the standard views, there may be special views may be available in the theme control which you can apply to show the lines. Ask your site expert if there are any available.

Details

Here are a few points about how it works:

• You must have at least two connected lines from the same plan selected.
• You can select multiple groups of 2 or more connected lines.
• You can select groups from more than one plan.
• When two or more plans are used, comparisons between the plans are calculated. The most recent plan is used as the reference.
• For radial curves, IAT uses curve chord for IA calculation.

Important! The tool uses recorded bearings only. As IA calculation is for same plan lines subtending a common point, the IA is accurate. Comparisons between plans is done by finding the common subtended points and the line ending points, then comparing the IA values.

Warning: Comparisons of IA expect a logical selection of lines for analysis. If you just click and drag, to select a large number of lines where more than path through the line are selected, the IAs will be correct but the comparisons will not.