MATH CHAPTER 11 PDF

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What is the rotocenter? The fixed point O.

What is the angle of rotation? The angle indicating amount by which you rotate.

What are the properties of rotation? 1) Rotation is determined by 4 points: P, P', Q, and Q'. 2) Rotations other than the identity have exactly one fixed point, which is O. 3) Rotations are proper. 4) A 360 degree rotation is the identity motion.

What is a proper rigid motion? One where left/right and clockwise/counterclockwise orientations are preserved.

What is a translation? Dragging an object in a specified direction by a specified amount.

What is the vector of translation? A quantity with length and direction that points in the direction of translation.

What are the properties of translation? 1) Completely determined by 2 points. 2) No fixed points.

3) Proper. 4) A translation of v followed by -v is the identity motion.

What is a glide reflection? A rigid motion that is obtained by combining a translation with a reflection. The axis of a reflection (l) must be parallel to v.

How are intermediate points denoted for glide reflections? With an asterisk (*)

What are the properties of glide reflections? 1) Completely determined by 4 points: P, P', Q, and Q'. 2) No fixed points. 3) Improper. 4) A glide reflection with vector v and axis l has an inverse with vector -v and axis l.

What is the symmetry of an object? A rigid motion that moves and object back onto itself. There is a type of symmetry for each rigid motion, in 2D.

What is a reflection symmetry? When one half of an image is the reflection of the other half.

What is rotational symmetry? When an object looks the same after a rotation....