面积
miànjī · HSK 3
area
📐 面 = surface + 积 = accumulate → accumulated surface = area
面 means surface or face; 积 means to accumulate or product (as in multiplication). Together 面积 is literally the accumulated surface — the math sense of area. Same 积 appears in 体积 (volume) and 乘积 (product).
面 — enclosure 囗 + 自 (nose/face inside)
Originally a pictograph showing a face framed by an outline, with 自 (nose) inside representing the central feature of the face. The early meaning was 'face,' which extended to 'surface,' 'side,' and 'aspect.' In simplified Chinese, 面 also absorbed 麵, adding the meaning 'flour/noodles.'
积 — grain radical 禾 + 责 (phonetic)
积 is a semantic-phonetic compound: 禾 (grain) gives the meaning, while 责 supplies the sound. It originally referred to piling up harvested grain, which extended to the general sense of 'accumulate' or 'amass'. The simplified form replaced the older 積.