First, the method of square number

A figure with many squares is large, and vice versa.

Second, the overlapping method

Overlapping two graphs, it seems that which graph has a large surface area will have a large area.

Third, segmentation and replacement method.

A graphic is divided and then moved to form another graphic or similar graphic shape, and then compared.

Fourth, the spelling method (using two graphics to spell a graphic, the third graphic is larger.

Small)

Without calculating the graphic area, we can compare the areas of two graphics by the above method.