Transformations and Similarity

Dilate the figure by a scale factor of 3 with the origin as the center of dilation. What are the coordinates of the image?

• A'(9,9) B'(18,18) C'(27,9)

• A'(6,6) B'(9,9) C'(12,6)

• A'(0,0) B'(3,3) C'(6,0)

• A'(1,1) B'(2,2) C'(3,1)

State the coordinate of the image of the given point B (-10,-6) under a dilation with center at the origin with the given scale factor k = 1/2.

• (5,3)

• (20,12)

• (-20,-12)

• (-5,-3)

∆BCD contains the points: B(2,3) C(2,1) D(5,1). If the triangle is reflected across the x-axis, what will B' be?

• B'(2, -3)

• B'(-2, 3)

• B'(-2, -3)

• B'(2, 3)

What does similar mean?

• corresponding sides are proportional and corresponding angles are congruent

• corresponding sides and angles are congruent

• sames shape

• neither sides or angles are congruent

Describe the Transformation

• Translation

• Rotation

• Reflection

Which of the statements is true about the graphed triangles?

• They are similar, because one can be obtained by dilating the other about the origin with a scale factor of 2.

• They are similar, because one can be obtained by dilating the other about the origin with a scale factor of 1/2.

• They are not similar, because one can be obtained by dilating the other about the origin with a scale factor of 2.

• They are not similar, because one can be obtained by dilating the other about the origin with a scale factor of 1/2.

What is the rule for the dilation pictured below?

• (x, y) → (½x, ½y)

• (x, y) → (x + 2, y + 2)

• (x, y) → (2x, 2y)

• (x, y) → (2x, 3y)

Are the following similar? Why or why not?

• Yes. All pairs of corresponding angles are congruent and the sides are proportional.

• No, the corresponding angles are not equal.

• No, the ratios of the corresponding sides are not equal.

What is the scale factor from the triangle to the left to the triangle on the right?

• 2

• 3/2

• 2/3

• 1/2

What is the scale factor from ΔDEF to ΔABC?

• 1/2

• 7/3

• 2

• 10/3