尺短寸长

• 尸(body lying down; prone body)RADICAL
• 乚(hook; curve)ASSOCIATIVE

A ruler is imagined as a person lying straight with curved fingers marking the length.

• 矢(arrow point; arrowhead)RADICAL
• 豆(bean; small object)PHONO-SEMANTIC

An arrow's short tip is the size of a bean — that is the meaning of short.

• 寸(thumb; inch)ASSOCIATIVE

Drawing a hand with a small dot marking the pulse-measurement point represents the unit of measurement called a cun.

• 长(long hair; old person (pictographic))ASSOCIATIVE

An old person with long hair cascading down symbolizes something lasting a long time.