Geometry terms Flashcards
Alternate interior angles.
Alternate interior angles lie within a pair of lines and on opposite sides of a transversal.
Angle of rotation
The angle of rotation is the number of degrees a figure is rotated
Congruent
Two two-dimensional figures are congruent (≅) if the second can be obtained from the first by a sequence of rotations, reflections, and translations
Center of rotation
The center of rotation is a fixed point about which a figure is rotated.
Corresponding angles
Corresponding angles lie on the same side of a transversal and in corresponding positions.
Dilation
A dilation is a transformation that moves each point along the ray through the point, starting from a fixed center, and multiplies distances from the center by a common scale factor. If a vertex of a figure is the center of dilation, then the vertex and its image after the dilation are the same point
Enlargement
An enlargement is a dilation with a scale factor greater than 1. After an enlargement, the image is bigger than the original figure.
exterior angle of a triangle
An exterior angle of a triangle is an angle formed by a side and an extension of an adjacent side.
Image
An image is the result of a transformation of a point, line, or figure
Line of reflection
A line of reflection is a line across which a figure is reflected.
Reduction
A reduction is a dilation with a scale factor less than 1. After a reduction, the image is smaller than the original figure
Reflection
A reflection, or flip, is a transformation that flips a figure across a line of reflection
Remote interior angles
Remote interior angles are the two nonadjacent interior angles corresponding to each exterior angle of a triangle
Rotation
A rotation is a rigid motion that turns a figure around a fixed point, called the center of rotation.
Same-side interior angles
Same-side interior angles are in the interior of two lines on the same side of a transversal
Scale factor
The scale factor is the ratio of a length in the image to the corresponding length in the original figure
Similar
A two-dimensional figure is similar (∼) to another two-dimensional figure if you can map one figure to the other by a sequence of rotations, reflections, translations, and dilations.
Transformation
A transformation is a change in position, shape, or size of a figure. Three types of transformations that change position only are translations, reflections, and rotations
Translation
A translation, or slide, is a rigid motion that moves every point of a figure the same distance and in the same direction
