Math 242 – Lab 3
Laying Out a Baseball Field
I.
Introduction
In the previous activities you have learned some of the basic tools and functions of the
Geometer’s Sketchpad. In this activity you will be applying those tools to create a diagram. At
the same time you will also be doing some geometric investigation. You should look up how
translations work in Sketchpad before you begin. This is a useful tool.
II.
Laying out a baseball field
The following instructions are taken directly from the Official Rules for Major League Baseball:
When location of home base is determined, with a steel tape measure
127 feet, 3 3/8 inches in desired direction to establish second base. From
home base, measure 90 feet toward first base; from second base, measure
90 feet toward first base; the intersection of these lines establishes first
base. From home base, measure 90 feet toward third base; from second
base, measure 90 feet toward third base; the intersection of these lines
establishes third base.
Your task is to follow these directions to create a drawing for a baseball infield. Make your
drawing to scale using 1 cm to represent 10 feet.
Hints: - these can be useful
1) In the edit menu choose preferences and set the precision for angles, length and
other to the most accurate.
2) Convert the measurements to feet (using decimals) before beginning.
3) Begin by creating a point that will be home plate. Translate that point by 12.728
cm at a fixed angle of 90. This point will be second base.
4) Use translations to establish all other distances.
5) According to the rules no angles are measured during the construction of the
diamond.
6) The instructions suggest that the location of 1st and 3rd base can be found by
intersecting circles.
III.
Checking your Drawing
In a separate document (MS Word), answer the following questions in complete and welldeveloped sentences. You can measure the drawing you made.
1) How long are the base lines? Does your construction guarantee this?
2) Measure the angles at each base. What are the measures of these angles?
3) Is the distance from 1st base to 3rd base the same as the distance from home base
to 2nd base? MEASURE IT! Are they close or exactly the same.
4) The MLB rules specify “The infield shall be a 90 foot square.” Does the
construction supplied in the rules meet this requirement? If yes, tell why. If no,
explain the discrepancy.
IV.
More Detail
Use the following specifications to complete your scale drawing. You may “embellish” the
drawing with any extra features you like for extra credit, but it must include the following
elements.
Hint: These details are very fine. You can construct them in a larger scale and then use
the dilate function to reduce the size.
1) Backstop. It is recommended that the distance from home base to the backstop,
and from the base lines to the nearest fence, stand or other obstruction on foul
territory shall be 60 feet or more.
2) Slide area. The “slide area” around the bases is a 13-foot radius within the 90foot square.
3) Home Plate. The home plate area is a 26-foot diameter circle centered at home
base.
4) Pitcher’s mound. The front pitching rubber should be 60 feet 6 inches from
home plate measured in the direction of second base. The diameter of a pitcher's
mound clay is 18 feet, with 10 feet from the front of the pitching rubber, toward
home plate and 8 feet behind.
5) Outfield. The outfield grass line is a 95-foot radius measured from the front of
the pitching rubber. Any Playing Field constructed by a professional club after
June 1, 1958, shall provide a minimum distance of 325 feet from home base to the
nearest fence, stand or other obstruction on the right and left field foul lines, and
a minimum distance of 400 feet to the center field fence.
Before turning in your project copy the entire drawing into
V.
Finishing your drawing
Completing parts I – III will earn you a maximum of 85% of the points for this lab. Part IV is
worth 10% more. To earn the final 5% you must complete part V.
In this part you will be adding extended features to your baseball field representing the batters
box, base pads and the pitchers rubber. The descriptions are as follows:
1) Home Base. Home base shall be marked by a five-sided slab of whitened rubber.
It shall be a 17 inch square with two of the corners removed so that one edge is
17 inches long, two adjacent sides are 8 1/2 inches and the remaining two sides
are 12 inches and set at an angle to make a point. It shall be set in the ground
with the point at the intersection of the lines extending from home base to first
base and to third base; with the 17 inch edge facing the pitcher's plate, and the
two 12 inch edges coinciding with the first and third base lines.
2) Bases. First, second and third bases shall be marked by white canvas bags,
securely attached to the ground. The first and third base bags shall be entirely
within the infield. The second base bag shall be centered on second base. The
bags shall be 15 inches square.
3) Pitchers Plate. The pitcher's plate shall be a rectangular slab of whitened
rubber, 24 inches by 6 inches. It shall be set in the ground so that the distance
between the pitcher's plate and home base (the rear point of home plate) shall be
60 feet, 6 inches.
4) Batters Box and Catchers box. See diagram below.
Hint: Since these features are relatively small, it may be difficult to create the pitcher’s mound,
home plate and the bases with the necessary accuracy. You will find it easier to construct larger
on a scale of 1 cm = 1 foot and use a dilation to “shrink” the feature to the appropriate size. You
will need to carefully consider the location of the dilation center so that the constructed object
dilates to the appropriate position.
When you have finished your drawing save it and print it. Finished sketches are due on
Friday, September 29, 2006
Please save a copy of the file in the folder x:\dropoff\mat\burnsd\Mat 242\lab 3\. Use your last
name and first initial as the file name.
For Extra Credit - Coloring can be added to enhance the look of the field and make it look like a
particular field you like. The easiest way to add color is to copy your field and paste it into
“Paint” or some other drawing program. Color can also be added to the field in the GSP
program by creating polygonal regions and coloring the interior. You can also look up the
stadium dimensions of your favorite baseball field and modify your drawing to make it look as
realistic as you like.
Helpful Diagrams:
8 ft.
10 ft.