Unit 1: Transformations in the Coordinate Plane Flashcards
(15 cards)
Transformation
A change in the position, size, or shape of a figure. Includes translations, reflections, rotations, and dilations.
Preimage
The original figure before a transformation is applied.
Image
The figure after the transformation.
Isometry (Rigid Motion)
A transformation that preserves distance and angle measure (shape and size stay the same).
Examples: Translation, reflection, rotation
Translation
A “slide” — moves every point of a figure the same distance in the same direction.
Reflection
A “flip” — a mirror image over a line (called the line of reflection).
Rotation
A “turn” — rotates a figure around a fixed point (called the center of rotation) by a certain angle.
Dilation
A transformation that changes the size of a figure but not its shape. It uses a scale factor and a center of dilation.
• Enlargement: scale factor > 1
• Reduction: scale factor between 0 and 1
Scale Factor
The ratio of the image’s size to the preimage’s size in a dilation.
Center of Dilation
The fixed point in a dilation from which all points are expanded or contracted.
Congruent figures
Figures that are the same size and shape. Rigid motions produce congruent figures.
Similar figures
Figures that have the same shape but not necessarily the same size. Dilations produce similar figures.
Line of Symmetry
A line that divides a figure into two mirror-image halves.
Rotational Symmetry
A figure has this if it can be rotated (less than 360°) and still look the same.
Composition of Tansformations
Applying two or more transformations in a sequence
