A literal is the actual value of a specific data type.  For example, 'A', 'B', '3', and '!' are all literal characters; 234, -5, and 6789 are literal integers; 3.14 and 2.71 are literal doubles; true and false are literal booleans; and "Hello, world!" and "Catch ya later" are literal strings.

			Arithmetic expressions are combinations of numbers with arithmetic operators.  Arithmetic expressions evaluate to a numerical value.

			3 + 4 evaluates to 7.  17 - 3 evaluates to 14.  5 * 8 evaluates to 40.  3*(5+2) evaluates to 21.

			Java has the standard arithmetic operators +, -, *, /.  It also has %, the remainder or modulus operator.  E.g., 7 % 5 evaluates to 2 because when 7 is divided by 5 the quotient is 1 and there is a remainder of 2.  The usual order of operations applies:  multiplication and division come first (in order from left to right), then addition and subtraction (in order from left to right).

			Note than an integer divided by an integer results in an integer (any fraction or remainder is discarded).

			A number without a decimal point is assumed to be an int, unless it's too big, and then it's a long.

			A number with a decimal point is assumed to be a double, unless it's followed by a f or F, and then it's a float.

			When an int is added to a double, the int is promoted to a double before the addition, and the result is a double.

			An int can be assigned to a double with no loss in precision.

			However, assigning a double to an int could result in a loss of precision, so a cast is required.

			Variables are declared (memory is allocated for them and a name is associated to them) by typing the name of the data type, then a space, then the name of the variable.

			Variables may also be initialized by assigning them values at the time they are declared.

			Values are assigned to variables by putting the variable on the left side of an = sign and the value to be assigned on the right side.

			An int can be assigned to a double with no loss in precision.

			However, assigning a double to an int could result in a loss of precision, so a cast is required.

			You can compare two values with relational operators:  a < b means "a is less than b", a > b means "a is greater than b", a <= b means "a is less than or equal to b", a >= b means "a is greater than or equal to b", a == b means "a equals b", a != b means "a is not equal to b".

			The result of a relational expression is a boolean result:  true or false.

			DrawingPen class code

			1 - Drawing a square in main using a DrawingPen object

			2 - Using a for-loop in main to repeat selected instructions

			3 - Moving the for-loop that draws the square into drawSquare(), a separate method, and calling it from main

			4 - Calling the drawSquare() method from a for-loop in main with rotations between calls

			5 - Passing a parameter to the drawSquare(int side) method to draw squares of variable sizes

			6 - Drawing rotating squares of decreasing sizes to form a spiral

			7 - Drawing smaller, centered squares inside of larger squares

			8 - Drawing smaller squares inside of larger squares with one corner fixed

			9 - Drawing smaller, centered, rotated squares inside of larger squares

			Study the code and output of parts 1-8 of Using the DrawingPen class, above.

			Write 8 programs which produce output similar to each of the examples given above, but use equilateral triangles instead of squares.

			Send me your source code and sample output for each of the 8 examples.

			Extra credit:  Write a java program which uses the DrawingPen class to create the output in example 9 based on equilateral triangles rather than squares.