# Area calculations

You can compute an area defined by points, lines or arcs. If required, you can subdivide the computed area using a parallel line or a hinge point.

To compute a surface area you must use Compute volume.

1. To compute an area:

   From the map:

   1. Select the points, lines, or arcs that define the perimeter of the area to be calculated.

      Select items in the order that they occur on the perimeter. When selecting lines or arcs, select them in the correct direction.

   2. Tap and hold in the map and then select Area calculations.

   From the menu:

   1. Tap and select Cogo / Area calculations.

   2. Select the points that define the area perimeter, in the order that they occur on the perimeter.

      You can only select points to define the area when you open the Area calculations screen from the menu.

   3. Tap Calc.

   The computed area and perimeter are shown. The arrows on the lines indicate the order in which the points were selected.

2. To change how distances are calculated, tap Options. See Cogo settings.
3. Enter a name for the area in the Name field.
4. To store the area without subdividing it, tap Store.
5. To subdivide the area:
   1. Tap the subdivide method – Parallel or Hinge.
   2. In the New area field, enter the size of the new area, which will be subtracted from the total area.
   3. If you selected:
      - The Parallel method, tap the line that defines the parallel line.
      - The Hinge method, tap the point that defines the hinge point.

      The New area that you entered is shaded blue. New intersection point(s) are displayed with a red circle, and labeled Pt1, Pt2, and so on.

      See the example of an area subdivided using the Hinge method below:

      If lines intersect or cross over, the software attempts to compute the correct area and subdivide the area, but in some cases may give the wrong results. Make sure that the graphical representation looks correct and then double‑check the results if you have concerns that they may not be correct.

   4. If the subdivided area you require is the complement of the area displayed, tap the Swap area button to switch areas.
   5. Tap Continue.
   6. To store the intersection point(s), enter their name(s) and then tap Save.
   7. If you do not want to save the intersection point(s), do not name them. Tap Close.

To view details about the original area and perimeter, new area and perimeter, intersection points, and an image of the area, go to Review job.