You're designing a package in Go that deals with various shapes like circles, squares, and triangles. Which approach would you use to define a common behavior for these shapes?

In Go, interfaces are a powerful tool for defining common behaviors across different types. By defining an interface with methods such as Area() or Perimeter(), each shape type can implement these methods according to its own logic. This approach allows for flexibility and polymorphism, enabling code to work with any shape that satisfies the interface contract. Using interfaces promotes cleaner code, decouples implementation details, and facilitates testing and extensibility.