基本几何形把值编码为边角与对称携带意义的闭合轮廓。欧几里得《几何原本》（约前300年）仍命名学校套件；现代界面在复用。
工作报告、广告与作业中适合图标、海报、练习纸、品牌标志。若需要编码数量时用图表，不要漂亮的三角，换一种形式。
Rules
- 规则 1 — Use 边角与对称携带意义的闭合轮廓 as one channel, not two.
- 规则 2 — Direct labels beat a distant legend.
- 规则 3 — Do not hide zero. If you break the axis, say so.
- 规则 4 — Colour encodes category or magnitude, not both.
- 规则 5 — Put the claim in the title, not just “基本几何形”.
- 规则 6 — Source and period, even in small type.
Palette
- 色板 1 — Categories: distinct hues. Sequences: one hue, changing value.
- 色板 2 — Diverging: a neutral centre, emphasis at both ends.
- 色板 3 — One brand colour plus greys beats a rainbow.
- 色板 4 — Check contrast on a projector and in greyscale print.
Type
- 文字 1 — Tabular figures for numbers. Do not pour body copy into the chart.
- 文字 2 — Titles as sentences; axes as short nouns.
- 文字 3 — For CJK, drop weight one step and leave tracking.
基本几何形: honour 边角与对称携带意义的闭合轮廓, and switch when 需要编码数量时用图表，不要漂亮的三角.