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4.5 Exploration, example #2

Directions

Use the applet below to construct a dilation by the given scale factor by following these directions:
  1. Use the line tool to construct a line that passes through point A (the center of dilation) and point B (a pre-image point)
  2. Use the segment tool to trace a segment from point A to point B (This is the equivalent of opening a compass up to that width)
  3. Use the compass tool to find an image point that is -1.5 times as far from the center of dilation as the pre-image. Use the point tool to mark that point on the applet. (Hint: a negative dilation is the same as a positive dilation but in the opposite direction from the center of dilation).
  4. Repeat this process for each of the other two pre-image points.
  5. Use the polygon tool to trace the final image.

Dilate triangle BCD by a factor of -1.5 from center A