Chapter 18

Question 1

types of rigid motion

Answer 1

translations, rotations, reflections

Question 2

transformations that preserve orientation

Answer 2

translations, rotations

Question 3

transformations that are isometries

Answer 3

translations, rotations, reflections

Question 4

to rotate 90˚ clockwise

Answer 4

make x –, then switch x and y

Question 5

to rotate 90˚ counter-clockwise

Answer 5

make y –, then switch x and y

Question 6

reflections across the y-axis

Answer 6

(x, y) -> (-x, y)

Question 7

reflections across the x-axis

Answer 7

(x, y) -> (x, -y)

Question 8

reflections across the line y=x

Answer 8

(x, y) -> (y, x)

Question 9

reflections across the line y = -x

Answer 9

(x, y) -> (-y, -x)

Question 10

shortcut for reflections

Answer 10

y - y coordinate + y

Question 11

theorem 1 parallel lines

Answer 11

reflections across 2 parallel lines are equivalent to doing a translation

Question 12

theorem 2 intersecting lines

Answer 12

reflections across 2 intersecting lines are equivalent to doing a rotation around the pt of intersection