Vocabulary
The process of manipulating a shape.
What is transformation?
This is the name given to the original shape before any translation or transformation happens.
What is preimage?
This simple, 4-letter word describes what happens to a shape during a reflection.
What is flip?
In geometry, a rotation is defined by two things: the number of degrees it turns, and this specific direction that goes the opposite way of a standard clock.
What is counterclockwise?
This is the math term for the specific number you multiply the original coordinates by to make a shape larger or smaller.
What is the scale factor?
The four sections of a graph.
What is a quadrant?
If you translate a point using the algebraic rule T(x + 5, y - 3), this is the exact direction and distance the point will move.
Right 5, Down 3
If you take Point C (4, -7) and reflect it over the y-axis, these are the coordinates of its image, C'.
C' (-4, -7)
When you rotate any point 180 degrees, both the x and y coordinates undergo this specific change.
They both change signs. (They are negated!)
If Point A is (3, -5) and it is dilated using a scale factor of 3, these are the coordinates of the image, A'.
A' (9, -15)
Figures that have the same shape but are different sizes.
What are similar figures?
If Point A (2, -4) is translated 4 units left and 6 units up, these are the coordinates of its new image, A'.
A' (-2, 2)
This is the name for the straight line that acts as the "mirror" that a shape flips over.
What is the line of reflection?
If you take Point A (3, 5) and rotate it 90 degrees clockwise, these are the coordinates of its image, A'.
A' (5, -3)
If Point Z is (-6, 18) and it is dilated using a scale factor of 1/3, these are the coordinates of the image, Z'.
Z' (-2, 6)
Matching sides of two different figures.
What are corresponding sides?
An image point is at A' (1, 8) after being translated using the rule (x + 1, y + 2). These are the coordinates of the pre-image point, A.
A (0, 6)
If the pre-image point is B (3, 4) and its reflected image is B' (3, -4), this axis was used as the line of reflection.
What is the x-axis?
If you rotate a shape 360 degrees in either direction, this is how the coordinates of the image compare to the pre-image.
They stay the same.
If the pre-image point is H (5, -15) and the new dilated image point is H' (1, -3), this is the exact scale factor that was used.
k = 1/5
What we call the final shape after transforming a figure two times in a row.
What is a double image?
B (0, 3) slides 3 units right to create image B'. Then, B' slides 7 units down to create the double image. These are the final coordinates of B''.
B'' (3, -4)
If a pre-image point sits directly on the line of reflection, this is what happens to its coordinates when it is reflected.
It stays the same.
Point B (2, -4) is rotated 90 degrees counterclockwise to create B'. Then, B' is rotated another 180 degrees to create the double image, B''. These are the final coordinates of B''.
B" (-4, -2)
Point B (-4, 8) is dilated using a scale factor of k = 0.5 to create image B'. Then, B' is slid 4 units down to create the double image, B''. These are the final coordinates of B''.
B" (-2, 0)