Transformation in Geometry Created by Ms. O. Strachan
Slide 3
Aim: Identifying and describing transformation For this lesson
we will: Rotate a geometric figure. Rotate a geometric figure.
Reflect a figure over a line of symmetry. Reflect a figure over a
line of symmetry. Translate a figure by sliding it to a different
location. Translate a figure by sliding it to a different location.
Use dilation by enlarging or reducing the size of a figure without
changing its form or shape. Use dilation by enlarging or reducing
the size of a figure without changing its form or shape.
Slide 4
Transformation A rule for moving every point in a plane figure
to a new location.
Slide 5
Translation A transformation that moves each point in a figure
the same distance in the same direction.
Slide 6
In a translation a figure slides up or down, or left or right.
No change in shape or size. The location changes. In graphing
translation, all x and y coordinates of a translated figure change
by adding or subtracting.
Slide 7
Reflection A transformation where a figure is flipped across a
line such as the x-axis or the y- axis.
Slide 8
In a reflection, a mirror image of the figure is formed across
a line called a line of symmetry. No change in size. The
orientation of the shape changes. In graphing, a reflection across
the x -axis changes the sign of the y coordinate. A reflection
across the y-axis changes the sign of the x-coordinate.
Slide 9
Rotation A transformation where a figure turns about a fixed
point without changing its size and shape.
Slide 10
In a rotation, figure turns around a fixed point, such as the
origin. No change in shape, but the orientation and location
change. Rules for rotating a figure about the origin in graphing.
Rules for 90 degrees rotation- Switch the coordination of each
point. Then change the sign of the y coordinate. Ex. A (2,1) to A (
1,-2)
Slide 11
Dilation A transformation where a figure changes size.
Slide 12
Dilation In dilation, a figure is enlarged or reduced
proportionally. No change in shape, but unlike other
transformation, the size changes. In graphing, for dilation, all
coordinates are divided or multiplied by the same number to find
the coordinates of the image.