This Java program demonstrates abstract classes and inheritance using a base class Shape and two subclasses: Triangle and Rectangle.
🔹 Classes: Shape: Abstract class with side, area, and perimeter. Declares calculateArea() and calculatePerimeter().
Triangle: Extends Shape, uses side and height. Calculates area and perimeter (assuming equilateral triangle).
Rectangle: Extends Shape, uses side (as length) and width. Calculates area and perimeter.
TestShape: Main class that creates and displays a triangle and a rectangle.
✅ Output: makefile Copy Edit Traingle: Area:3.0 Perimeter:9.0 Rectangle: Area:6.0 Perimeter:10.0