```I. Types of Shapes
A. Rectangular
1. Rectangles
a. Squares
b. Specification
i. Top/Left/Width/Height
ii. Top/Left and Bottom/Right corners
2. Ellipses
a. Circles
b. Specification
i. Ellipses: Same as rectangles
ii. Circles
1) same as rectangles
3. Arcs
a. Specification
i. Start Angle/End Angle
ii. Start Angle/Increment Angle
b. Java
i. Start Angle measured from 0 degress on X-axis (the horizontal)
ii. Positive increment = counter-clockwise
c. Arc Types
i. Chord: Line segment connects start and end points
ii. Open: No line segment between start and end point
iii. Pie: Line segments from start and end points to the center,
thus creating a pie shape
4. Text
5. Images
B. Lines
1. Arrows
a. Specification--One technique (see paper notes)
i. height - length along the line
ii. width - width of the arrow

b. Derivation of equations for the endpoints of an arrow (I will
first assume that the origin is positioned at the lower left
corner of the coordinate system, as is done in traditional
math. At the end I will convert the equations to reflect the
fact that the origin is actually at the upper left corner for
computer monitors).)
1) Equation for a line = P1 + d*t where t goes from 0 to 1,
d is a directional vector, and d = [P2.x - P1.x, P2.y - P1.y]
2) If d = (dx, dy), then the normal vector, n, to the line is (-dy, dx)
3) The unit directional vector is
(dx / sqrt(dx*dx+dy*dy), dy / sqrt(dx*dx+dy*dy))

4) ArrowPt1 = P2 - length * unit_d + width * unit_n
ArrowPt2 = P2 - length * unit_d - width * unit_n
5) Arrow = Polyline(ArrowPt1, P2, ArrowPt2)

6) Pseudo-code

dx = X2 - X1;
dy = Y2 - Y1;
line_length = sqrt(dx*dx + dy*dy)
normalized_dx = dx / line_length;
normalized_dy = dy / line_length;

ArrowX1 = X2 - arrowLength * normalized_dx - arrowWidth * normalized_dy
ArrowY1 = Y2 - arrowLength * normalized_dy + arrowWidth * normalized_dx
ArrowX2 = X2 - arrowLength * normalized_dx + arrowWidth * normalized_dy
ArrowY2 = Y2 - arrowLength * normalized_dy - arrowWidth * normalized_dx

7) Adjustment for Computer Monitors: Since the y-origin is
at the top of the screen, rather than the bottom of the screen,
I need to flip the signs for the length and width in the y-axis.
In other words, to move down the line from P2 to P1, I needed
to add the length in the y-direction, and then to move out
toward the top of the screen, I need to subtract the width in
the y-direction. Hence for a computer monitor, my final set
of equations should be:

ArrowX1 = X2 - arrowLength * normalized_dx - arrowWidth * normalized
_dy
ArrowY1 = Y2 + arrowLength * normalized_dy - arrowWidth * normalized_dx
ArrowX2 = X2 - arrowLength * normalized_dx + arrowWidth * normalized_dy
ArrowY2 = Y2 + arrowLength * normalized_dy + arrowWidth * normalized_dx

2. Polylines
a. Polygon: closes polyline
b. Join style is important attribute

C. Curves