Vocabulary

Transformation: A transformation is an operation that maps an original geometric figure, the preimage, onto a new figure called the image.

Dilation: A transformation that enlarges or reduces a figure by a scale factor.

Scale Factor: A scale factor is the ratio of the lengths of two corresponding sides of two similar polygons.

Similar: Figures that have the same shapee, but not necessarily the same size.

Congruent: Figures that have the same shape and same size. 

Concept

Identify the properties of transformation.

Rule

Identify and select the correct answer choice based on the properties of similarity and dilation.

Example

Which of the following is true when the scale factor of the dilation is equal to 1? 

Solution

By definition, when the scale factor of the dilation is 1, the dilated figure is the same size as the original. This makes sense because if we take the original figures measurements and multiply them by a scale factor of 1, multiplying by 1 does not change the value of a number.

Pre-requisite Skills

Congruence and Transformations (8.8.1)

Dilation (8.7.4)