Purpose To construct a planemetric map of an area using using simple devices.
Goal The percent of error will be less than 5%.
Constraints Pacing techniques—Sighting alignments
Materials
sighting device (ruler on edge)
magnetic compass
2 stakes
paper
large board (for paper)
metric tape measure
Procedures
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1. In the middle of the area to be mapped, pace off a distance over half the length of the area to be measured and place stakes at each end and refer to this as your base line.
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____
Decide on a scale and make the base line on your paper.
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2. From point A, sight in and draw a line along your point of sight to the four boundaries.
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3. Move to point B, align table and sight on the same objects. Mark only the points of intersection.
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4. Connect points of intersection.
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5. Using your scale, determine the distance around the perimeter.
Evaluation Determine the percent error.
|
section
|
scale
|
distance/scale
|
distance/true
|
% error
|
|
AB
|
5.0 cm
|
20 m
|
20 m
|
0
|
|
CD
|
9.0 cm
|
45 m
|
47 m
|
4.4%
|
|
DE
|
2.9 cm
|
11.6 cm
|
12.0 m
|
3.3%
|
|
EF
|
8.3 cm
|
33.2 cm
|
34.0 m
|
2.3%
|
|
CF
|
3.0 cm
|
12.0 m
|
11.5 m
|
4.3%
|
