Write java program that deal with different shapes. Shapes mean geometry shapes i.e. circle, rectangle, square, and triangle.

```
Circle: radius
Rectangle: height and width
Square: height
Triangle: base and height
```

All shapes have area but each shape has specific way for calculating the area:

```
Circle: ½ pie square *radius
Rectangle: height * width
Square: height * height
Triangle: ½ base *height
```

Finally, in the main program

1. Define all different kinds of shapes

2. Call Area method for all objects and print result .