1. In place of lecture, today you should attempt to implement the methods from the Complex class below that are in italics. 
    classDiagram
    class Complex{
        -real: double
        -imag: double
        -isPolar: boolean$
        +Complex()
        +Complex(real: double)
        +Complex(real: double, imag: double)
        +Complex(num: String)
        +toString() String
        +plus(addend: double) Complex*
        +plus(addend: Complex) Complex
        +minus(subtrahend: Complex) Complex*
        +equals(that: Complex) boolean*
        +getMagnitude() double
        +getAngle() double
        +setPolar() void$*
        +setCartesian() void$*
        +times(multiplicand: Complex) Complex
        +dividedBy(divsor: Complex) Complex
    }
    Once you have completed each method, check your implementation by watching this video
  2. More practice... implement the following class. Two students should be equivalent if they have the same ID. 
    classDiagram
    class Student{
        -firstname: String
        -lastname: String
        -id: int
        +Student(fullname: String, id: int)
        +Student(firstname: String, lastname: String, id: int)
        +toString() String
        +getFullname() String
        +setFirstname(firstname: String) void
        +setLastname(lastname: String) void
        +equals(that: Student) boolean
        +getId() int
    }
  3. More practice... implement the following class. You should ensure that the denominator is always greater than zero. 
    classDiagram
    class Fraction{
        -numerator: int
        -denominator: int
        +Fraction()
        +Fraction(num: int)
        +Fraction(num: int, den: int)
        +toString() String
        +plus(addend: Fraction) Fraction
        +minus(subtrahend: Fraction) Fraction
        +equals(that: Fraction) boolean
        +getValue() double
        +times(multiplicand: Fraction) Fraction
        +dividedBy(divsor: Fraction) Fraction
    }