法 (fǎ) is a broad noun meaning 'law' as a concept or system, and also 'method, way'. For the specific sense of written, formal law (statute), use 法律 (fǎlǜ) instead — 法 is more general and appears in many compounds (e.g. 宪法 'constitution'). The 'method' sense has no near-synonym among the listed siblings.