Circle Inversions with Reflections

Exercises

2. Expansion and contraction

Open the compass a radius of 9 or 10 cm.
Draw a semicircle near the bottom of the short side of a piece of paper.
Draw a small square near the circle on the same side as the center O.
Place the plastic (unbent) perpendicular to the paper, tangent to the circle near its middle.
Slowly bend the plastic to fit the semicircle.
Observe the changes in the image of the square.
Draw one of the apparent images of the square.
Are any of the image sides straight?
Compare the area of the image shape with that of the original square.
Click the right picture for an enlargement in a new wondow. Here blue plastic wasa used.
Repeat this experiment with the small square drawn on the side of the semicircle opposite the observer.
Compare the size of the inverted square and its image.

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