//******************************************************************************
//  Title:  Shape.java       
//  Author: Miguel A Rodriguez
//  Date:   1/1/2015
//  Course: CSC 112-001
//******************************************************************************
//  Description:
//****************
//            This is an abstract class containing two methods shared by most of the classes.
//         
// 
//******************************************************************************
   
   
//         UML Diagram for this helper class         
//          ***********************************************************************************     
//Class:      Shape
//          ***********************************************************************************
//Methods:
//            +computeArea(): double
//            +computePerimeter(): double
//          ************************************************************************************* 

public abstract class Shape
{
   abstract public double computeArea();
   abstract public double computePerimeter();
}

Create Shape.java