Chapter 9 Vocabulary Words
Terms
undefined, object
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- angle of rotation
- the angle between the line of sight and the horizontal when an observer looks upward
- Center of rotation
- a fixed point around which shapes move in a circular motion to a new position.
- Column matrix
- a matrix containing one column often used to represent an ordered pair or a vector, such as (x,y) = [x/y]
- Component form
- a vector expressed as an ordered pair (change in x, change in y)
- Dilation
- a transformation determined by a center point and a scale factor
- Direct isometry
- a isometry in which the image of a figure is found by moving the figure intact within the plane
- Direction
- the measure of the angle that a vector forms with the positive x-axis or any other horizontal line.
- Equal vectors
- vectors that have the same magnitude and direction
- Glide reflection
- a composition of a translation and a reflection in a line parallel to the direction of the translation
- Indirect isometry
- an isometry that cannot be performed by maintaining the orientation of the points, as a direct isometry
- Isometry
- a mapping for which the original figure and its image are congruent
- Line of reflection
- a line through a figure that separates the figure into two mirror images
- Line of symmetry
- a line that can be drawn through a plane figure so that the figure on one side is the reflection image of the figure on the opposite side
- Magnitude
- the length of the vector
- Parallel vectors
- vectors that have the same or opposite direction
- Point of symmetry
- the common point of reflection for all points of a figure
- Reflection
- a transformation representing a flip of figure over a point, line, or plane
- Reflection matrix
- a matrix that can be multiplied by the vertex matrix of a figure to find the coordinates of the reflected image
- Regular tessellation
- a tessellation formed by only one type of regular polygon
- Resultant
- the sum of two vectors
- Rotation
- a transformation that turns every point of preimage through a specified angle and direction about the fixed point, called the center of rotation
- Rotation matrix
- a matrix that can be multiplied by the vertex matrix of a figure to find the coordinates of the rotated image
- Rotational symmetry
- if a figure can be rotated less than 360 degrees about a point so that the image and the preimage are indistinguishable, the figure has rotational symmetry
- Scalar
- a constant multiplied by a vector
- Scalar multiplication
- multiplication of a vector by a scalar
- Semi-regular tessellation
- a uniform tessellation formed using two or more regular polygons
- Similarity transformation
- when a figure and its transformation image are similar
- Standard position
- when the initial point of a vector is at the origin
- Tessellation
- a pattern that covers a plane by transforming the same figure or set of figures so that there are no overlapping or empty spaces
- Transformation
- in a plane, a mapping for which each point has exactly one image point and each image point has exactly one preimage point
- Translation
- a transformation that moves all points of a figure the same distance in the same direction
- Translation matrix
- a matrix that can be added to the vertex of a figure to find the coordinates of the translated image
- Vector
- a directed segment representing a quantity that has both magnitude, or length, and direction