8.3C

Dilations Practice

Multiple Choice

Triangle ABC is dilated to produce triangle A'B'C' with scale factor 3/4 . Which describes the relationship between the two triangles?

• Triangle A'B'C' is an enlargement of triangle ABC

• Triangle A'B'C' is a reduction of triangle ABC

• Triangle A'B'C' is a mirror image of triangle ABC

Multiple Choice

Which is true about the scale factor when a figure is enlarged?

• The scale factor is zero.

• The scale factor is 1.

• The scale factor is larger than 1.

• The scale factor is smaller than 1.

Dilations create Similar Figures

• Corresponding angles are congruent

• Corresponding sides are proportional

• Since sides are proportional, we can write an equivalent proportion

Multiple Choice

Triangle PQR is similar to triangle DEF shown. Which describes the relationship between the corresponding sides of the two triangles?

Now Let's Practice more Dilation Rules

• Remember: dilation rules are the ONLY rule where x and y are MULTIPLIED by a coefficient

• Dilation rules will always look like this, where k is the scale factor:

• (x, y) --> (kx, ky)

Multiple Choice

Which of the following is the algebraic representation for a dilation?

• (x, y) → (x, 3y)

• (x, y) → (3x, 3y)

• (x, y) → (x, y - 3)

• (x, y) → (.5x, .4y)

Dilations also affect perimeter and area!

Make sure to find the perimeter/area before and after the dilation, then compare! It may help to draw a picture!

Multiple Choice

Rectangle ABCD has a length of 6 and a height of 5. It is dilated by a scale factor of 3.

What is true about the perimeter of A'B'C'D', the new rectangle?

• The perimeter of A'B'C'D' is the same as the perimeter of ABCD

• The perimeter of A'B'C'D' is the 3 times larger than the perimeter of ABCD

• The perimeter of A'B'C'D' is the 6 times larger than the perimeter of ABCD

• The perimeter of A'B'C'D' is the 9 times larger than the perimeter of ABCD

Multiple Choice

A triangle has a perimeter of P units. The triangle is dilated by a scale factor of 1/2.

Which expression could represent the perimeter of the new shape?

• $$\frac{1}{4}P$$ units

• $$\frac{1}{2}P$$ units

• 2P units

• 4P units

Multiple Choice

A rectangle is dilated by a scale factor of 2.

What happens to the area?

• doubles

• triples

• quadruples

• not enough information

Drag and Drop

In this figure, triangle TRS is the ​

Placeholder

, triangle T'R'S' is the ​

Placeholder

and a(n) ​

Placeholder

occurred.

Drag these tiles and drop them in the correct blank above

pre-image

image

enlargement

reduction

spin

flip

Multiple Choice

The point (8, 12) was dilated to become point (2, 3). What was the scale factor?

• ½

• ¼

• 4

• 2

Multiple Choice

A dilation produces a similar figure

• True

• False

Multiple Choice

Line segment GJ corresponds to

• Line segment YX

• Line segment WZ

• Line segment JI

• Line segment XW

Multiple Choice

Line segment HI corresponds to

• Line segment XY

• Line segment ZY

• Line segment WZ

• Line segment XW

Multiple Choice

Which of the following proportions could be used to find x?

Multiple Choice

A figure is dilated on a coordinate grid to create a similar, smaller figure. The figure is dilated using the origin as the center of dilation. Which rule could represent this dilation?

• A. (x, y) --> (1.5 - x, 1.5 - y)

• B. (x, y) --> (x - 10, y - 10)

• C. (x, y) --> (7/3x, 7/3y)

• D. (x, y) --> (0.75x, 0.75y)

Multiple Choice

A figure is reflected across the y-axis to create a new figure. Which rules describes this transformation?

• A. (x, y) --> (-x, y)

• B. (x, y) --> (x, -y)

• C. (x, y) --> (-x, -y)

• D. (x, y) --> (y, x)

Multiple Choice

Pentagon R'S'T'U'V' is a transformation of RSTUV. Which rule describes this transformation?

• A. (x, y) --> (x, -y)

• B. (x, y) --> (-y, x)

• C. (x, y) --> (-x, -y)

• D. (x, y) --> (y, -x)