AlgNet/GeoNet: A Union City School District Summer Enrichment Program
Using technology not simply to do things better, but to do better things.

"ISOMETRIES" OR "RIGID TRANSFORMATIONS" IN SKETCHPADTM

Rigid transformations are a way of moving a figure without changing its size or shape. These are also called isometries because they preserve the same measures for length and angles.

Reflection

To do a reflection, you need an object to reflect and a mirror in which to reflect it.

  1. At the left side of your sketch, construct the interior of an asymmetrical polygon (you can do this by constructing some points while holding the shift key down, then choosing Construct >> Polygon Interior).
  2. Next to this polygon, construct a vertical segment EF.
  3. Select segment EF (not the endpoints themselves). Then choose Transform >> Mark Mirror.
  4. Select your polygon, then choose Transform >> Reflect.

Rotation

To do a rotation, you need an object to rotate, a center of rotation around which to rotate it, and an angle by which to rotate it.

  1. At the left side of your sketch, construct the interior of an asymmetrical polygon.
  2. Somewhere in the sketch, construct a point.
  3. Select the point Then choose Transform >> Mark Center.
  4. Select your object and choose Transform >> Rotate. You'll be asked to choose an angle.

Translation

To do a translation, you need an object to translate and a vector by which to translate it.
  1. At the left side of your sketch, construct the interior of an asymmetrical polygon.
  2. Next to this polygon, construct a horizontal segment EF.
  3. Select the points E and F in that order. Then choose Transform >> Mark Vector.
  4. Select your object and choose Transform >> Translate.


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