In bronze inscriptions, it 平 is composed of 于 (airflow passing obstacles) and 八 (moving in separate directions). That’s to say, the airflow passes and disperses. Seal script suggests a comfortable（兮）and calm（一）tone. Regular script resembles an object with two equal halves. 平 serves as semantic component to form characters.
Characters formed by the phonetic component 平
评/評 萍 坪 苹/蘋 枰 呯 玶 岼 泙 胓 蚲 鲆/鮃 with the same pronunciation píng
砰 怦 抨 匉 with the same pronunciation pēng
伻 秤 bēng chèng