Home > Lessons > Dilations
Search | Updated December 22nd, 2018
    In this section of MATHguide, you will learn about dilations. Here are the topics within this page:

    Similar Figures -- a topic covered in another section -- can be described by the mathematics of dilations.

    Dilations have these features:

  • They have a center of dilation.
  • They have a scale factor.
  • There is the original figure and it's image figure.

    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.

      ideo: Dilations

    Here is a quiz that can be used to test your understanding of dilations.

      uiz: Dilations

    View these related lessons.

      esson: Reducing Fractions
      esson: Geometry Proofs
      esson: Proportions
      esson: Similar Figures
      esson: Areas and Lengths of Similar Figures
      esson: Volumes and Lengths of Similar Solids