Left phonetic
高 (gāo) — supplies the sound, shifting to qiāo through the velar series. Standalone
高 means 'tall, high' and pictographically depicts a tall watchtower. Same phonetic in
稿 (gǎo manuscript),
搞 (gǎo do/handle),
蒿 (hāo wormwood). Recognising
高 on the left cues the gāo/qiāo cluster.