Radicals ( Radical17) two strokes in Kanji;

dimensional, e.g.

www.jisho.org radical number 14 ... ;

directional, e.g.

;

logical, e.g.

cap;
lid;
to cover, so something can be underneath;

numerological, e.g.

2;

structural, e.g.

supporting part of a roof;

Radicals;