WHOLE CHARACTER
平
flat; level; even (不倾斜,无凹凸); fair; equal; peaceful (均等; 安定); usual; ordinary (一般的,普通的)
平 is flat, level, and fair: 平安 'safe and sound', 公平 'fair', and 水平 'level; standard'.
Taught as one complete written unit (5 strokes). ZDIC: 会意; the source's detailed account of the old form is history, not a modern split.