4.1: Reflections
A reflection is also called a what? (flip, turn, or slide)
Flip
A translation is also called a what? (flip, turn, or slide)
Slide
A rotation is also called a what? (flip, turn, or slide)
Turn
Folding a figure in half to see if the halves line up exactly the same
Line Symmetry
Which variable tells you how far to travel left and right on the coordinate plane?
X
When you reflect over a vertical line, what variable stays the same?
Y - coordinates
T/F: A transformation is a translation if the shape has turned on its side.
False
Which direction do you have to rotate to use the rotation formulas?
Counterclockwise
Daily Double
Free Points!
What is creating a mirror image of a shape on the coordinate plane?
Reflection
How do you reflect over the line y = x?
Flip the x and the y coordinates
Translate the point (12 , 5) in the TV <-4 , 7>
(8 , 12)
What is the formula for a 90° clockwise rotation?
(x , y) --> (y , -x)
How many lines of symmetry does a square have?
4
What is the origin on a coordinate plane?
(0 , 0)
Reflect the point (14 , 12) in the line y = x
(12 , 14)
Translate the point (-4 , -2) in the TV <-6 , 8>
(-10 , 6)
Rotate the point (-4 , 8) 90° counterclockwise.
(-8 , -4)
How many lines of symmetry does a rhombus have?
2
What is the distance from the original points to the new points of a translation called?
Translation Vector
Reflect the point (-2, 5) in the line x = 3
(8 , 5)
If you draw lines between corresponding points of a translated shape, they will be what?
Parallel
Rotate the point (1, -4) 180° about the point (0 , 2)
(-1 , 8)
How many lines of symmetry does a pentagon have?
5
Rigid motion that reflects a shape onto itself
Symmetry