Compute area and update dimensions
Input
r = Rectangle(3, 4) r.area
Output
12
Area is computed as 3 * 4 = 12. If width or height change, area will reflect the new values.
Full lesson preview
Implement a Computed Property for a Derived Value
Create a Rectangle class with width and height and a read-only computed area property.
Python practice10 minMethods & PropertiesBeginnerLast updated April 7, 2026
Problem statement
Implement a Rectangle class that stores width and height and exposes a read-only area property computed as width * height.
Requirements:
- Rectangle(width, height) constructor stores numeric width and height.
- width and height should be settable attributes (public) that accept numeric values.
- Implement an @property called area that returns the current product of width and height.
- The area must always reflect the current width and height values (i.e., it is computed on access, not cached).
Task
Learn to implement a computed @property that derives a value from instance state and always reflects updates.
Examples
Input format
A Python expression creating or inspecting a Rectangle instance, evaluated and its return value compared to the expected output.
Output format
The string representation of the returned value is compared to the expected output.
Constraints
- width and height are numeric (int or float).
- area should return int or float depending on inputs.
- No external libraries.
- Use @property for area and compute it on access.
Samples
Sample 1
Input
Rectangle(2.5, 3).area
Output
7.5
Area computed with float inputs yields a float result.