8th grade Ch 6 L4

Find the coordinates of the vertices of each figure after a dilation with the given scale factor k. Then graph the original image and the dilation.

A(3, 5), B(0, 4), C(−2, −2); k = 2

What are the coordinates of the dilated vertices?

• A'(6, 10), B'(0, 8), C'(-4, -4)

• A'(5, 7), B'(2, 6), C'(0, 0)

• A'(3, 10), B'(0, 4), C'(-2, -4)

• A'(9, 15), B'(0, 12), C'(-6, -6)

Find the coordinates of the vertices of each figure after a dilation with the given scale factor k. Then graph the original image and the dilation.

J(0, −4), K(0, 6), L(4, 4), M(4, 2); k = 1/4

What are the coordinates of the dilated vertices?

• J'(0, -1), K'(0, 1.5), L'(1, 1), M'(1, 0.5)

• J'(0, -2), K'(0, 3), L'(2, 2), M'(2, 1)

• J'(0, -4), K'(0, 6), L'(4, 4), M'(4, 2)

• J'(0, -0.5), K'(0, 0.75), L'(0.5, 0.5), M'(0.5, 0.25)

Mrs. Bowen’s homeroom is creating a Web page for their school’s Intranet site. They need to reduce a scanned photograph so it is 720 pixels by 320 pixels. If the scanned photograph is 1,080 pixels by 480 pixels, what is the scale factor of the dilation?

• The scale factor is 2/3.

• The scale factor is 3/2.

• The scale factor is 1/2.

• The scale factor is 1/3.

Dilations are similar to scale drawings because:

• they both change the size but not the shape of a figure.

• they both change the shape but not the size of a figure.

• they both only apply to three-dimensional objects.

• they both require measuring angles.

Find the coordinates of the vertices of each figure after a dilation with the given scale factor k.

• C'(2, 8), A'(4, 4), T'(10, 10)

• C'(4, 8), A'(2, 4), T'(8, 10)

• C'(2, 4), A'(4, 8), T'(10, 2)

• C'(8, 2), A'(4, 10), T'(2, 4)

Find the coordinates of the vertices of each figure after a dilation with the given scale factor k.

• R'(0.75, 0.75), S'(0.75, 5.25), T'(3.75, 5.25), U'(3.75, 0.75)

• R'(1.5, 1.5), S'(1.5, 10.5), T'(7.5, 10.5), U'(7.5, 1.5)

• R'(0.5, 0.5), S'(0.5, 3.5), T'(2.5, 3.5), U'(2.5, 0.5)

• R'(1, 1), S'(1, 7), T'(5, 7), U'(5, 1)

A graphic designer created a logo on 8 1/2 by 11-inch paper. In order to be placed on a business card, the logo needs to be 1 7/10 inches by 2 1/5 inches. What is the scale factor of the dilation?

• The scale factor is 1/5.

• The scale factor is 1/2.

• The scale factor is 2/5.

• The scale factor is 1/10.

Darian wants to build a regulation-size pool table that is 9 feet in length. The plans he ordered are 18 by 36 inches. What is the scale factor of the dilation he must use to build the regulation pool table?

• 6

• 4

• 8

• 12

A triangle has vertices A(-2, 3), B(0, 0), and C(1, 1). Find the coordinates of the triangle if it is reflected over the x-axis, then dilated by a scale factor of 3.

• A'( -6, -9 ), B'( 0, 0 ), C'( 3, -3 )

• A'( 6, 9 ), B'( 0, 0 ), C'( -3, 3 )

• A'( -6, 9 ), B'( 0, 0 ), C'( 3, 3 )

• A'( -2, -3 ), B'( 0, 0 ), C'( 1, -1 )

A triangle has vertices A(-2, 3), B(0, 0), and C(1, 1). Find the coordinates if the original triangle is dilated by a scale factor of 3, then reflected over the x-axis.

• A'( -6, -9 ), B'( 0, 0 ), C'( 3, -3 )

• A'( 6, 9 ), B'( 0, 0 ), C'( 3, 3 )

• A'( -6, 9 ), B'( 0, 0 ), C'( 3, 3 )

• A'( -2, -3 ), B'( 0, 0 ), C'( 1, -1 )