Dilations on Graph

A scale factor of less than one means

• that the image will be larger than the pre-image.

• That the image will be the same as the pre-image.

• That you need to subtract that amount off  of each side.

• That the image will be a reduction of the pre-image.

(x, y) -> (2x, 2y)

What does the coefficient 2 mean?

• move points 2 units to the right and 2 units up

• scale factor is 2, creating a new figure half the size of the original

• scale factor is 2, making a figure twice the size of the original

• rotate the figure 2 quadrants

If the scale factor is greater than one, the new figure will be

• reduction

• enlargement

• scale

• not proportional

The __________ is the ratio of a length of the image to the corresponding length on the original figure.

• reduction

• enlargement

• scale factor

• center of dilation

Which is FALSE about dilations?

• The shape is the same.

• The size changes.

• The sides of the shape get larger or smaller.

• The angles of the shape get larger or smaller.

In the diagram below, CD is the image of AB after a dilation of scale factor k with center E. Which ratio is equal to the scale factor k of the dilation?

• EC : EA

• BA : EA

• EA : BA

• EA : EC

On the graph below, point A(3, 4) and BC with coordinates B(4, 3) and C(2, 1) are graphed. What are the coordinates of B' and C' after BC undergoes a dilation centered at point A with a scale factor of 2?

• B'(5,2) and C'(1, -2)

• B'(6, 1) and C'(0, -1)

• B'(5, 0) and C'(1, -2)

• B'(5, 2) and C'(3, 0)

A line segment is dilated by a scale factor of 2 centered at a point not on the line segment. Which statement regarding the relationship between the given line segment and its image is true?

• The line segments are perpendicular, and the image is one-half of the length of the given line segment.

• The line segments are perpendicular, and the image is twice the length of the given line segment.

• The line segments are parallel, and the image is twice the length of the given line segment.

• The line segments are parallel, and the image is one-half of the length of the given line segment

The line whose equation is 3x – 5y = 4 is dilated by a scale factor of 5/3 centered at the origin. Which statement is correct?

• The image of the line has the same slope as the pre-image but a different y-intercept.

• The image of the line has the same y-intercept as the pre-image but a different slope.

• The image of the line has the same slope and the same y-intercept

  as the pre-image.

• The image of the line has a different slope and a different y-intercept from the pre-image.

A line that passes through the points whose coordinates are (1,1) and (5, 7) is dilated by a scale factor of 3 and centered at the origin. The image of the line

• is perpendicular to the original line

• is parallel to the original line

• passes through the origin

• is the original line