Construct a class named Circle with attributes named radius, diameter and area. Include a constructor that sets the radius to 1 and calculates the other two values. Include get and set methods for all the attributes. The setRadius() method not only sets the radius, it also calculates the other two values. The diameter of a circle is twice the radius and the area of a circle is pi multiplied by the square of the radius. Use the Math class PI constant for this calculation.

At most, a class can contain ____________ method(S). 0 1 2 any number of

a. Write a FractionDemo program that instantiates several Fraction objects and demonstrates that their methods work correctly. Create a Fraction class with fields that hold a whole number, a numerator, and a denominator. In addition: Create properties for each field. The set access or for the denominator should not allow a 0 value; the value defaults to 1. Add three constructors. One takes three parameters for a whole number, numerator, and denominator. Another accepts two parameters for the numerator and denominator; when this constructor is used, the whole number value is 0. The last constructor is parameterless; it sets the whole number and numerator to 0 and the denominator to 1. (After construction, Fractions do not have to be reduced to proper form. For example, even though 3/9 could be reduced to 1/3, your constructors do not have to perform this task.) Add a Reduce() method that reduces a Fraction if it is in improper form. For example, 2/4 should be reduced to 1/2. Add an operator+() method that adds two Fractions. To add two fractions, first eliminate any whole number part of the value. For example, 2 1/4 becomes 9/4 and 1 3/5 becomes 8/5. Find a common denominator and convert the fractions to it. For example, when adding 9/4 and 8/5, you can convert them to 45/20 and 32/20. Then you can add the numerators, giving 77/20. Finally, call the Reduce() method to reduce the result, restoring any whole number value so the fractional part of the number is less than 1. For example, 77/20 becomes 3 17/20. Include a function that returns a string that contains a Fraction in the usual display format—the whole number, a space, the numerator, a slash (D, and a denominator. When the whole number is 0, just the Fraction part of the value should be displayed (for example, 1/2 instead of 0 1/2). If the numerator is 0, just the whole number should be displayed (for example, 2 instead of 2 0/3). b. Add an operator*() method to the Fraction class created in Exercise 11a so that it correctly multiplies two Fractions. The result should be in proper, reduced format. Demonstrate that the method works correctly in a program named FractionDemo2. c. Write a program named FractionDem03 that includes an array of four Fractions. Prompt the user for values for each. Display every possible combination of addition results and every possible combination of multiplication results for each Fraction pair (that is, each type will have 16 results).

Write a program named SalespersonDemo that instantiates objects using classes named Real EstateSalesperson and GirlScout. Demonstrate that each object can use a SalesSpeech() method appropriately. Also, use a MakeSale() method two or three times with each object, and display the final contents of each objects data fields. First, create an abstract class named Salesperson. Fields include first and last names; the Salesperson constructor requires both these values. Include properties for the fields. Include a method that returns a string that holds the Salespersons full name—the first and last names separated by a space. Then perform the following Create two child classes of Salesperson: Real EstateSalesperson and Girl Scout. The Real EstateSalesperson class contains fields for total value sold in dollars and total commission earned (both of which are initialized to 0), and a commission rate field required by the class constructor. The Girl Scout class includes a field to hold the number of boxes of cookies sold, which is initialized to 0. Include properties for every field. Create an interface named ISell able that contains two methods: SalesSpeech() and MakeSale(). In each Real EstateSalesperson and Girl Scout class, implement SalesSpeech() to display an appropriate one- or two-sentence sales speech that the objects of the class could use. In the Real Estatesalesperson class, implement the MakeSale() method to accept an integer dollar value for a house, add the value to the Real EstateSalespersons total value sold, and compute the total commission earned. In the Girl Scout class, implement the MakeSale() method to accept an integer representing the number of boxes of cookies sold and add it to the total field.