1. addition: This method decomposes an irregular figure into several basic regular figures, calculates their areas respectively, and then adds them to get the area of the whole figure. For example, to get the area of the whole graph, you only need to get the area of the upper semicircle first, then the area of the lower rectangle, and then add them up.
2. Subtraction: This method regards the area of irregular figure as the difference of several basic regular figures. For example, if you want to find the shadow area, you only need to find the sector area first, and then subtract the triangle area.
Third, direct solution: this method is to directly solve the area of irregular graphics as a whole according to known conditions. As shown in the upper right of the next page, the area of the shadow part is found to be a triangle with a base of 7 and a height of 14, and its area can be directly solved as follows:
4. Recombination method: This method is to disassemble the irregular figure, reassemble it into a new figure according to the specific situation and calculation needs, and try to find out the area of this new figure. For example, if you want to find the area of the shadow in the picture below, you can take it apart and then subtract it to find its area.
The above is a simple explanation for everyone, I believe everyone has mastered it!