Circular Outline: The basic structure of a pie chart, representing the whole data or 100% proportion.

Sector Areas (Slices): Represent different parts of the whole, with each sector's size proportional to the data it represents.

Legend: Explains the data categories or meanings represented by each sector in the pie chart.

Common pie charts can be divided into basic pie charts, donut charts, composite pie charts, and Nightingale rose charts based on visual presentation.

A pie chart with a hollow center, similar to a basic pie chart, also displays the proportion of each part through sector areas. The blank central area can be used to add additional information, such as the overall value, title, icon, etc., enhancing the information transmission capacity of the chart.

A composite pie chart is usually a combination of a main pie chart and a secondary pie chart. The main pie chart shows the main categories and their proportions, while the secondary pie chart further subdivides one or several sectors of the main pie chart.

Also called a polar area chart, it divides the polar coordinate plane into several equal-angle areas and fills the corresponding equal-angle areas based on different data sizes. The stretched length is proportional to the value size of the category, which can better highlight the value differences between different categories.

Use with caution: Only show the proportion relationship of a small number (≤6 categories) in the whole, avoiding multiple categories or precise comparisons.
Simplify categories: Merge minor items into 'Others' to ensure distinguishable sectors.
Highlight sorting: Arrange by proportion from large to small, with key categories at the front or highlighted.
Clear coloring: Use contrasting colors to distinguish sectors, avoiding too many colors.
Clear labels: Directly label percentages and category names, using guide lines if necessary to avoid overlap.
Prefer alternatives: Use bar charts for many categories, line charts for trends.
Verify total: Ensure percentages sum to 100%, with an error ≤1%.