Similar Figures -- a topic covered in another section -- can be described by the mathematics of dilations.
Dilations have these features:
When we refer to the original figure, of say a triangle, we call the original figure △ABC. We call the image figure △A'B'C'. The second triangle is pronounced, "triangle A-prime, B-prime, C-prime."
A characteristic called scale factor informs us of the relationship between the original figure and its image. The scale factor is typically called the k-value.
When the k-value is 0 < k < 1 [greater than zero but less than one], the image figure is smaller than the original figure. When the k-value is k > 1 [greater than one], the image figure is greater than the original figure. This information is encapsulated within the diagram that follows.
The video below will demonstrate exactly how dilations work.
Here is a quiz that can be used to test your understanding of dilations.