## Lab 3

Write a Java class named "Circle" that models a circle. Your class should
have only one instance variable; the radius of the circle.

Your class should include the following methods

- a default constructor that sets the radius to 1.0
- an initialization constructor whose only parameter is the radius
- a copy constructor
- one setter (setRadius)
- four getters (getRadius, getDiameter, getCircumference, and getArea)
- toString (you may choose your own string representation)

Your class file should include appropriate documentation comments for the
class as a whole and for each method. The Java class implementation is worth 10
points and appropriate documentation comments are worth an additional 5 points.

#### Geometric Formulas

diameter = 2.0 * radius

circumference = 2.0 * π * radius

area = π * radius^{2}

#### Use Math.PI as the value of π

The value of π is defined as a constant (named PI) in the Math class. Class
constants are accessed by specifying the name of the class followed by a period
followed by the name of the constant (ClassName.ConstantName). In Java the value
of π is given by Math.PI.

#### Use the Math.pow Function to Perform Exponentiation

There is no exponentiation operator in Java. However, there is a function
named "pow" in the Math class that performs exponentiation. It has two double
arguments and returns the value obtained by raising the first argument to the
power of the second argument. For example, Math.pow(a, b) returns the value of
a^{b} where a and b are double values.

### Submitting Your Work

Send me your "Circle.java" file as an attachment to an email message whose
subject is "Lab03".