Content of the Lesson Plan

Transformation

Moving a shape so that it is in a different position, but still has the same size, area, angles and line lengths. Turn, flip or slide are the basic moves. This is an example of a turn (rotational) transformation. These are Transformations: Rotation Turn! Reflection Flip! Translation Slide! After any of those transformations (turn, flip or slide), the shape still has the same size, area, angles and line lengths. Rotation "Rotation" means turning around a center: The distance from the center to any point on the shape stays the same. Every point makes a circle around the center. Here a triangle is rotated around the point marked with a "+" Reflection Reflections are everywhere ... in mirrors, glass, and here in a lake. ... what do you notice ? Every point is the same distance from the central line ! ... and ... The reflection has the same size as the original image The central line is called the Mirror Line ... Translation In Geometry, "Translation" simply means Moving ... ... without rotating, resizing or anything else, just moving. To Translate a shape: Every point of the shape must move: the same distance in the same direction. To see how this works, try translating different shapes here:   Resizing The other important Transformation is Resizing (also called dilation, contraction, compression, enlargement or even expansion). The shape becomes bigger or smaller: Resizing Congruent or Similar If one shape can become another using only Turns, Flips and/or Slides, then the two shapes are called Congruent. Two shapes are Similar if you need to Resize for one shape to become another (you may also Turn, Flip and/or Slide). So, if one shape can become another using transformation, the two shapes might be Congruent or just Similar If one shape becomes another ... The shapes are ... ... using only Rotate, Reflect and/or Translate  Congruent ... using a Resize (may also Rotate, Reflect and/or Translate) Similar SOURCE: http://www.mathsisfun.com/geometry/translation.html