Square
A square is a specific two-dimensional shape. Square should be implemented as a subclass
of TwoDimensionalShape, a concrete class. A square has equal sides in both dimensions.
This is how to create a square:
public Square( int x, int y, int side )
/* use super constructor to set up x, y, and both dimensions
using side */

Method setSide sets each dimension to be side via dimension setters. Method getSide returns one of the three
dimensions via one dimension getter.
/*
I don't know how to change my dimensions to be called sides. Can anyone help?/

You don't change what the dimensions are called, you just take a value for side and use it to set both dimensions to the same value.