convex angle
Geometric term for an angle less than 180 degrees; used in mathematics and technical contexts.
All interior angles of a triangle are convex angles.
Standard kanji spelling using 凸 (convex).
Variant spelling using 突 (protruding); less common than 凸角.
Compound of 凸 (convex) and 角 (angle). The reading とっかく is the on'yomi of the characters.