1.4 Dilations

1.4 Dilations

Dilations will enlarge or reduce your image on the coordinate plane. 

Remember!

Poll

Which transformations do you like the most so far?

• Translations (Slides)

• Reflections (Flips)

• Dilations (Stretch or shrinks)

• Rotations (Turns)

Multiple Choice

A scale factor of 1/2 reduces a figure.

• True

• False

Multiple Choice

The "image" is the shape before the dilation.

• True

• False

Multiple Choice

The _________ is the ratio of a length of the new figure to the corresponding length on the original figure.

• reduction

• enlargement

• scale factor

• center of dilation

Multiple Choice

When the dilation has a scale factor greater than one, the dilation is an enlargement.

• True

• False

Multiple Choice

When the scale factor of a dilation is less than one, the dilation is a reduction.

• True

• False

Multiple Choice

When the scale factor is negative, what happens to the figure?

• Enlarges

• Reduces

• Reflects

• Rotates 180 degrees

Fill in the Blank

If a dilation has the rule

$$\left(x,y\right)\rightarrow\left(2.5x,\ 2.5y\right)$$  what is the scale factor?

Fill in the Blank

What is the scale factor from the small fry to the large fry?

Multiple Choice

If the triangle ABC is dilated using a scale factor of k=2, what will be the coordinates of A' after the transformation?

(Click the picture to enlarge it)

• A'(1.5, -1.5)

• A' (-6, 6)

Multiple Choice

A(1,2) is a point on a triangle. If the triangle is dilated by a scale factor of k =4, what is the coordinate of A'?

• A' (0.25, 0.5)

• A' (-4, -8)

• A' (4, 8)

Multiple Choice

What is the image of K(6, 8) after a dilation of k = 1/2 ?

• K' (4, 3)

• K' (12, 16)

• K' (3, 4)

Multiple Choice

What is the image of D (-6, 4) after a dilation of k = 3 ?

• D' (18, 12)

• D' (-18, 12)

• D' (-18, -12)

Poll

How do you feel about dilations?