Unit 3 - Rigid Motions - Symmetry

Question 1

How can a figure be symmetrical?

Answer 1

If a figure undergoes a rigid motion and maps onto itself

Question 2

How can you find out if a figure is symmetrical? (2)

Answer 2

1. Draw a line of reflection
2. Draw a Perp. Bis. of a point & through LOR

Question 3

Definition of Line Symmetry (3)

Answer 3

1. A figure has line symmetry
2. If it maps onto itself when it undergoes a reflection
3. On a line called the line of symmetry

Question 4

Definition of Rotational/Point Symmetry (3)

Answer 4

1. A figure has rotational symmetry
2. Undergoes a rotation of 0 degrees < Rotation < 360 degrees
3. And maps onto itself

Question 5

Definition of Order of Symmetry (2)

Answer 5

1. Num. of times figure maps onto itself
2. During a rotation of 360 degrees

Question 6

Definition of Magnitude of Symmetry

Answer 6

1. Num. of degrees figure has to be rotated
2. To maps onto itself

Question 7

How many times does a figure have to map itself in order to be considered to have Order of Symmetry?

Answer 7

2 or more

Question 8

How do you find magnitude if you know order?

Answer 8

360/Order

Question 9

How do you find order if you know magnitude?

Answer 9

360/Magnitude

Question 10

How do you draw a line of symmetry based on a point?

Answer 10

Draw a line through the point and the midpoint of the line opposite to it.