There are generally three methods to calculate the area of combined graphics: one is direct calculation; The second is to cut or repair the combined graph to get a graph which is convenient for calculating the area; Third, it cannot be calculated directly or it is difficult to calculate. You can try to subtract the area of the graph that is easy to calculate from the area of the graph that contains it.

There are many ways to calculate the area of combined graphics. Common methods are "division" and "addition".

The geometric figures of mathematics in primary schools are triangle, rectangle, square, parallelogram, trapezoid, diamond, circle and fan. These geometric figures are generally called basic figures or regular figures, and our area and perimeter are directly calculated by corresponding formulas.

Segmentation is to divide this figure into several basic figures. The simpler the sub-graph, the simpler the problem-solving method will be, and the relationship between the sub-graph and the given conditions should be considered.

Supplementary method, that is, by adding a simple graph, makes the whole graph become a big regular graph.

Apply what you have learned to solve the practical problems of combined graphics in life.

The size of irregular graphic area can be estimated correctly.

The area of irregular graphics can be calculated by calculating the grid.

The content of irregular figure area calculation is mainly based on the grid diagram, such as Beijing, so the grid diagram can help to establish the calculation method of irregular figure area.