What is the difference between strict and stringent and rigid ?Feel free to just provide example sentences.

Strict and stringent both are used with rules and regulations. however strict is used to define a person who follows these rules and regulations extremely closely while also demanding the same of others. "I have a very strict teacher" means your teacher demands the students to follow school rules. Stringent on the other hand is about the rules and regulations themselves. "These school rules are very stringent" meaning the school rules are very precise in what they demand. Lastly rigid is mostly used to define physical objects."The structure is very rigid" meaning the structure does not tend to move alot. However rigid can still also be used like strict and stringent. so this the most general usage.