凸
KANJI DETAIL
convex
On readingとつ5 strokesN1
Radical 凵 · open boxStroke order
Loading the stroke order for 凸.
Japanese readings
- On reading
- とつ
- Kun reading
- None
Study notes
1. Origins, structure, and basic meaning
- Structure:
凸is a five-stroke character with a middle that projects outward; its on-reading isとつ. - Basic usage: It describes an outward bulge, as in
凸レンズ(とつれんず), a convex lens.
2. Common pitfalls and similar expressions
- Convex and concave
凸indicates a projection and凹a recess. Comparing their central outlines helps distinguish the directions.
- Reading the word for an uneven surface
- For a bumpy road or uneven board,
凸凹is readでこぼこin this context. Its reading is not built by reusing theとつin凸レンズ.
- For a bumpy road or uneven board,