Definition
Angle of Rotation
The smallest angle needed for the figure to rotate onto itself
The perpendicular bisector of the segment joining every point and its image
Line of Reflection
A figure has ________ if there is an isometry that maps the figure onto itself
Symmetry
Switch the coordinates
y=x
What is the coordinate form for a figure that moves left 4 and up 3?
(x,y) -- (x-4, y+4)
Image
A figure that results from a transformation
A transformation that moves all points or a figure the same distance in the same direction
Translation
If a figure can be folded so that the two halves match exactly, the fold is called a _______.
Line of Symmetry
Multiply both coordinates by -1
origin
In the triangle KLM with vertices K (4,2), L (1,3), and M (2,1) rotated 90 counterclockwise, what are the new coordinates?
K` (-2,4), L` (-3,1), M` (-1,2)
Isometry
Another word for congruent
A transformation made up of successive transformations
Composition
If a figure can be rotated less than 360 degrees about a point so that the image and the pre-image are indistinguishable, the figure has ______.
Rotational symmetry
Switch the coordinates AND multiply both by -1
y=-x
Point A is a vertex of a polygon. Point R is the image of A after the dilation. Find the scale factor of the dilation. A (9,12) and R (3,4)
k=1/3
Pre-Image
a figure that undergoes a motion or transformation
The common point of reflection for all points of a figure
Point of Symmetry
The _________, is the movement of a figure in a plane from its original position to a new position.
Transformation
Multiply the y-coordinate by -1
x-axis
Identify the order and magnitude of the rotational symmetry for a regular 20-gon
order: 20
magnitude: 18
Regular Polygon
A polygon where all sides and angles are congruent
A pattern that covers a plane by transforming the same figure or set of figures so that there are no overlapping or empty spaces
Tessellation
__________ is a mapping for which a geometric figure and its image are congruent.
Congruence transformation
Multiply the x-coordinate by -1
y-axis
Square SQUR is translated left 6 to S`(-4,2), Q`(-1,2), U`(-1,-1), and R`(-4,-1). Find the coordinates of S, Q, U, and R.
S (2,2), Q (5,2), U (5,-1), R (2,-1)