Download PMI Reflections Activity Lab Part 1

PMI Reflections Activity Lab
Part 1: Paper Folding and Reflections
Materials:
• Square of Tracing Paper / Patty Paper
• Straightedge/Ruler
• Protractor
• Pencil
Procedure
• Use a piece of tracing paper and a straightedge. Using less
than half a page, draw a large, scalene triangle. Label its
vertices D, E and F.
•
Fold the paper so that your triangle is covered. Trace ΔDEF
with your straightedge.
•
Unfold your paper and label the traced points corresponding to
D, E and F as D’, E’ and F’ respectively.
ΔD’E’F’ is the reflection image of ΔDEF. The
fold is the reflection line.
Exercises
1. Use a ruler to draw DD’.
Measure the perpendicular distances from D to the fold and from D’ to the fold.
What do you notice?
2. Measure the angles formed by the fold and DD’. What do you notice?
Geometry - Transformations
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3. Repeat Exercises 1 and 2 for E and E’ and for F and F”. List what you find about the
pairs of angles and the pairs of segments.
4. Make a conjecture: How is the reflection line related to the segment joining a point and
its reflected image?
Part 2: Paper Folding and Reflections
Materials:
• Sheet of Regular Paper
• Straightedge/Ruler
• Compass
• Pencil
Procedure
• On regular paper, draw a simple shape
or design made of segments (on less
than half he page).
•
Draw a reflection line near your figure.
•
Use a compass and a straightedge to
construct a perpendicular to the
reflection line through one point of your
drawing.
Exercises
5. Explain how you can use a compass and the perpendicular you drew to find the
reflection image of the point you chose.
Geometry - Transformations
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6. Find the reflection images for the points of your shape.
7. Connect the image points corresponding to the connections in your original figure and
complete the image. Check the accuracy of your reflection image by folding the paper
along the reflection line and holding the paper to the light.
Geometry - Transformations
~3~
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