Rotational Symmetry

Reflection

Reflection and Rotation

Sequence of Transformations

100

Reflect over the line

y=-x

200

Reflect over the y-axis.

200

Rotate point *P* 90º clockwise around point *C*.

300

What angles of rotational symmetry are there for a regular pentagon?

Multiples of 72° (72, 144, 216, 288, 360)

300

Reflect triangle *ABC *over the line:

y=x

and label the image *A'B'C'*

300

Reflect over the y-axis and then rotate clockwise 90° around *P'*

400

What angles of rotational symmetry are there for a regular hexagon?

Multiples of 60° (60, 120, 180, 240, 300, 360)

400

Reflect quadrilateral *ABCD *over the line:

y=2+x

and label the image *A'B'C'D'*

400

Reflect triangle *ABC *over the line:

y=x

and label the image *A'B'C'.*

Rotate *A'B'C'* 180° counter-clockwise around the origin and label the image *A''B''C''*

400

Find a sequence of transformations that will carry triangle *RST* onto triangle *R’S’T’*.
Clearly describe the sequence of transformations.

Possible answer:

Translate left 8 so *S* coincides with* S'*

Reflect across *S'T'* so R lands on *R'*

500

If a regular polygon has an angle of rotational symmetry that is 40°, how many sides does the polygon have?

9 sides

500

Reflect point *P* over line *j*.

500

Reflect quadrilateral *ABCD *over the line:

y=2+x

and label the image *A'B'C'D'.*

Rotate quadrilateral *A'B'C'D' *counter-clockwise 90° around (-2, -3) as the center of rotation and label the image *A''B''C''D''.*

500

Find a sequence of transformations that will carry triangle *RST *onto triangle R’S’T’. Clearly describe the sequence of transformations.

Possible answer:

Translate up 8 units so *T* coincides with *T'*

Rotate clockwise 90° about *T'* until *TR* coincides with *T'R' *

Reflect across *T'R'* so *S* lands on *S'*

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