Command calculation command _ calculation command daquan

What command does Cad calculate the area?

In the process of drawing, it is often necessary to query and calculate the area of the graph. Let me introduce it.

First, look directly at the area of the graph.

If the drawing is a closed circle, polyline, spline, region and fill, you don't need to use the query region command. You can view the area and perimeter directly in the property panel (CTRL+ 1). Not only closed figures can, but also arcs and unclosed polylines have area characteristics.

If you want to copy the area and length numbers to other places, you can use the LIST query command list (shortcut key li).

The advantage of LI is that it is not only convenient to copy the area perimeter parameters, but also can query multiple graphs at one time.

Second, the query AREA command

CAD provides a special command to query the AREA: area, and the shortcut key is AA. But this command is not used for closed graphics, and it is too troublesome to use this command for non-closed graphics. On the contrary, this command is not used much. In fact, this command also has some very useful functions, such as area accumulation and area subtraction. It is still necessary to let everyone know.

Let's look at the options for the query area. After executing the query area command, the command prompt is as follows:

Specify the first angle or [object (O)/ increased area (A)/ decreased area (s)]; ：

From the prompt, we can see that there are two ways to query the area:

One is to specify the boundary directly in the drawing;

One is to select a closed object.

In addition, the area can be increased or decreased. Which form we choose depends on what kind of graph the boundary of the area we want to query is made of.

If the boundary is a closed figure, such as a circle, a closed polyline or an area, you can directly select an object to query the area. As we can see, at the end of the command line is

After the above prompt appears, we enter it directly, which will prompt us to choose an object. We can get the area and perimeter by choosing a closed figure.

CAD improvement tutorial-how to explain CAD command prompt

However, if the boundary is not a closed figure, but consists of intersecting lines or individual lines, arcs or polylines, there are two options:

One is to draw a closed boundary directly by specifying corner points when querying the area, so as to get the area.

One is to find a way to convert the area boundary into a closed figure with other commands.

If it is some simple intersecting figures, we can directly specify the intersection point when querying the area. The operation method is also very simple: first, make sure to turn on object snapping, check the intersection point, and then enter AA to pick up several corners of the area in turn.

The boundary of this area is four straight sides. Specify four points, and then press enter to get the area. We pay attention to the command prompt. The command to specify the boundary of a region is basically the same as the command to specify the boundary of a polyline. We can also define lines and arcs, but we have deleted the width setting of polylines. In addition, when we define three points, we will give a parameter of total (t), which means we can get the area now. We don't need to enter the t parameter, just press the space bar or press enter to get the result.

Although defining boundaries provides the same drawing options as polylines, not all graphics can be drawn in this way. Even if we just turn a straight line into an arc, it is difficult to draw this boundary with the area command.

Similar to the enclosed area with a space in the middle, we can use the Boundary)(BO) command to generate multi-segment LInes or areas, but if it is converted into multi-segment lines or areas, we can directly know the area in the property box or use the li (list query list) command, so there is no need to use the area query command.