Write a program that fills the window with a large ellipse, with a black outline and filled with your favorite color. The ellipse should touch the window boundaries, even if the window is resized.
Implement a graphical application that simulates a cash register. Provide a text field for the item price and two buttons for adding the item to the sale, one for taxable items and one for nontaxable items. In a text area, display the register tape that lists all items (labeling the taxable items with a *), followed by the amount due. Provide another button for starting a new sale.
Write a graphical application to implement a currency converter between euros and U.S. dollars, and vice versa. Provide two text fields for the euro and dollar amounts. Between them, place two buttons labeled > and < for updating the field on the right or left. For this exercise, use a conversion rate of 1 euro = 1.42 U.S. dollars.