Chapter 9

Question 0

Rotations about the origin

180 degrees

Answer 0

(x,y) —> (-x,-y)

Question 1

Rotations about the origin

270 degrees clockwise or
90 degrees counterclockwise

Answer 1

(X,Y) –> (-Y, X)

Question 2

Rotations about the origin

90 degrees clockwise or 270 degrees counterclockwise

Answer 2

(x,y) —> (y,-x)

Question 3

Reflections over the y-axis

Answer 3

(x,y) —> (-x,y)

Question 4

Reflections over x-axis

Answer 4

(x,y) —> (x,-y)

Question 5

Reflections over the y=x

Answer 5

(x,y) —> (y,x)

Question 6

Rotation about the origin means…

Answer 6

Counterclockwise

Question 7

Angle of rotation

Answer 7

The angle through which a preimage is rotated to form the image

Question 8

Center of rotation

Answer 8

A fixed point around which shapes move in a circular motion to a new position

Question 9

Composition of transformation

Answer 9

The resulting transformation when a transformation is applied to a figure and then another transformation is applied to its image

Question 10

Glide reflection

Answer 10

The composition of a translation followed by a reflection in a line parallel to the translation vector.

Question 11

Line of reflection

Answer 11

A line in which each point on the preimage and its corresponding point on the image are the same distance from this line

Question 12

Line of symmetry

Answer 12

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

Question 13

Magnitude of symmetry

Answer 13

The smallest angle through swhich a figure can be rotated so that it maps into itself

Question 14

Order of symmetry

Answer 14

The number of times a fugure can map into itself as it rotates from 0 degrees to 360 degrees

Question 15

Plane symmetry

Answer 15

Symmetry in a three-dimensional figure that occurs if the figure can be mapped into itself by a reflection in a plane

Question 16

Rotational symmetry

Answer 16

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.

Question 17

Symmetry

Answer 17

A figure has symmetry if there exists a rigid motion- reflection translation rotation or glide reflection that maps the figure into itself

Question 18

Translation vector

Answer 18

The vector in which a translation maps each point to its image.

Question 19

Order

Answer 19

How many times it matched up during a full rotation

Number of sides

Question 20

Magnitude

Answer 20

The smallest angle through which a figure can be rotated do it maps into itself

Magnitude= 360/order