Final answer:
Following the ideas of Legalism contributed to the downfall of the Qin dynasty through the use of cruel punishments to enforce strict laws.
Step-by-step explanation:
The downfall of the Qin dynasty during the reign of Emperor Shi Huangdi was contributed by following the ideas of Legalism, which focused on cruel punishments to enforce strict laws.
Learn more about Legalism's contribution to the downfall of the Qin dynasty