#62MediumClasses· Polymorphism

Inheritance & Polymorphism: Shape Hierarchy

Build a small class hierarchy and use it polymorphically. - An abstract base class `Shape` with abstract methods `area()` and `perimeter()`, and a `describe()` method that returns `"<Name>: area=<area>, perimeter=<perimeter>"` with both numbers formatted to two decimal places. - `Circle(radius)`, `Rectangle(width, height)`, `Square(side)` (a subclass of `Rectangle`) and `Triangle(a, b, c)` (area by Heron's formula). Then write `describe_shapes(shapes)`. Each item is a list such as `["circle", 1]`, `["rectangle", 2, 3]`, `["square", 4]` or `["triangle", 3, 4, 5]`. Create the matching object and collect `describe()` for each, in order. If a triangle's sides break the triangle inequality (one side is at least the sum of the other two), use `"Triangle: invalid sides"` instead. `describe_shapes` must not contain shape-specific formulas: it creates objects and calls the same method on all of them.

Input format

`shapes`: a list of `[kind, ...dimensions]` lists with positive numbers.

Output format

A list of description strings.

Examples

Input: shapes = [["circle",1],["rectangle",2,3]]

Output: ["Circle: area=3.14, perimeter=6.28","Rectangle: area=6.00, perimeter=10.00"]

Circle area is pi * r^2 = 3.14 and circumference 2 * pi * r = 6.28.

Input: shapes = [["square",4],["triangle",3,4,5],["triangle",1,2,3]]

Output: ["Square: area=16.00, perimeter=16.00","Triangle: area=6.00, perimeter=12.00","Triangle: invalid sides"]

A square is a rectangle with equal sides. 1 + 2 is not greater than 3, so the last triangle is invalid.

Constraints

0 <= len(shapes) <= 100
0 < dimension <= 1000

#python
#oop
#inheritance
#polymorphism
#abc