Transformations and Similarity Unit Test

15 of 1515 of 15 Items

Question
Line AB
is on the coordinate plane and does not pass through the origin. Line AB
is dilated with a scale factor of 3 and a center of dilation at the origin to create line A′B′
. Describe the effects of the dilation on Line AB
. If line AB
was dilated with a scale factor of 13
, how would your answer change?(4 points)

1 answer

When line \( AB \) is dilated with a scale factor of 3 and a center of dilation at the origin, the following effects occur:

  1. Change in Length: The length of line segment \( AB \) will be multiplied by the scale factor of 3. So, if the original length of line \( AB \) is \( L \), the new length of line \( A'B' \) will be \( 3L \).

  2. Position of Points: Each point on line \( AB \) will be moved away from the origin by a factor of 3. Specifically, if point \( A \) has coordinates \( (x_A, y_A) \), after dilation, the new coordinates of point \( A' \) will be \( (3x_A, 3y_A) \). The same applies for point \( B \).

  3. Orientation and Slope: The slope of line \( AB \) will remain the same because dilation is a uniform scaling transformation. The line will still be parallel to its original configuration but simply stretched away from the origin.

If line \( AB \) were dilated with a scale factor of \( \frac{1}{3} \) instead, the following changes would occur:

  1. Change in Length: The length of line segment \( AB \) would now be multiplied by the scale factor of \( \frac{1}{3} \). So, the new length of line \( A'B' \) would be \( \frac{1}{3}L \).

  2. Position of Points: Each point on line \( AB \) would move closer to the origin. For example, point \( A \) at \( (x_A, y_A) \) would be transformed to \( \left(\frac{1}{3}x_A, \frac{1}{3}y_A\right) \). The same applies for point \( B \).

  3. Orientation and Slope: The slope of line \( AB \) would remain unchanged as well, with the line remaining parallel to its original configuration but scaled down towards the origin.

In summary, a dilation of \( AB \) with a scale factor greater than 1 (like 3) results in the line segment being stretched away from the origin, while a scale factor less than 1 (like \( \frac{1}{3} \)) compresses the segment toward the origin. The orientation remains consistent in both scenarios.