Pie & donut encodes values as angle (and area) of a circle slice. Playfair 1801; Florence Nightingale’s coxcomb is a polar cousin, 1858.
In reports, ads and assignments it fits two to five parts that sum to a meaningful whole. Skip it when many similar slices, 3-D pie, or comparing two pies.
Principles
- Encoding — Pie & donut encodes angle (and area) of a circle slice.
- History — Playfair 1801; Florence Nightingale’s coxcomb is a polar cousin, 1858
- Fit — two to five parts that sum to a meaningful whole
- Shared baseline — The eye compares length and position more accurately than area.
- Audience — PowerPoint, Excel or Google Sheets and Meta, Google and retail print share the same geometry.
Misconceptions
- Pretty equals true — Decoration rarely persuades; it slows reading.
- 3-D helps — Perspective distortion wrecks comparison. Keep it flat.
- More series is richer — Do not stack stories. One Pie & donut, one claim.
- Default palette is fine — Rainbow defaults fail color-blind viewers and grey print. Change Excel or Google Sheets defaults.
Why it matters
- Work — Work: two to five parts that sum to a meaningful whole. Readable in four minutes in PowerPoint.
- Ads — Ads: one number and one shape speak first in Meta, Google and retail print.
- School — School: for lab reports and poster boards, pick the form that answers the rubric.
- Craft — Craft: honour angle (and area) of a circle slice and decoration falls away.
Pie & donut: honour angle (and area) of a circle slice, and switch when many similar slices, 3-D pie, or comparing two pies.