Rotations and Reflections
9-12.G-CO.3 Given a rectangle, parallelogram, trapezoid,
or regular polygon, describe the rotations and reflections
that carry it onto itself.
David Arnold
Important Vocabulary
Rotate
Parallelogram
Reflect
Trapezoid
Axis of Symmetry
Regular Polygon
Line of Symmetry
Center of Rotation
Rectangle
Angle of Rotation
Applying Vocabulary
Rotate- a motion of a certain space that
preserves at least one point.
Reflect- inverting an object with respect to a
plane; each element is transferred
perpendicularly through the plane to a point
Applying Vocabulary
Axis of Symmetry- the two sides of a graph on
either side of the axis of symmetry look like
mirror images of each other
Line of Symmetrythe imaginary line where you
can fold the image and have
both halves match exactly
Confused on axis of symmetry?
Check out this video!
Applying Vocabulary
Rectangle- a plane figure with four straight sides
and four right angles, especially one with unequal
adjacent sides, in contrast to a square
Regular polygona polygon that is equiangular
(all angles are equal in
measure) and equilateral (all
sides have the same length).
A star is a great
example of a
regular polygon
Applying Vocabulary
Parallelogram- a four-sided plane rectilinear
figure with opposite sides parallel
Trapezoid- a quadrilateral with only one pair of
parallel sides.
Applying Vocabulary
Center of Rotation- in a rotation, the point that
does not move. The rest of the plane rotates
around this one fixed point
Applying Vocabulary
Angle of Rotation- is a measurement of the
amount, the angle, by which a figure is rotated
counterclockwise about a fixed point, often the
center of a circle
Check out these additional videos
and links for further practice and
understanding
Rotation Video: https://www.youtube.com/watch?v=QoGDZ-Q8yRk
Reflection of Symmetry:
https://www.youtube.com/watch?v=ciJZWN__73s
Transformation Worksheet: http://cdn.kutasoftware.com/Worksheets/Geo/12All%20Transformations.pdf