Dilation is a transformation that changes the size of an object. It involves stretching or shrinking an object along its axes. It can be represented by a scale factor.
What is Dilation?
Scale Factor: The ratio of two lengths and measures the amount of scaling that takes place. Axes: The plural form of axis, which is an imaginary line in a two dimensional figure that divides it into two equal halves. Transformation: A change in the position, size, or shape of a figure.
Concepts:
What do you think is the most important characteristic of a dilation?
- The shape of the dilation
- The scale factor
- The center of the dilation
Dilation can also refer to the process of increasing the size of something, such as a lake or ocean. The opposite of dilation is contraction. Dilation can also occur in time – when time passes more slowly or quickly than usual.
Fun facts:
Draw / write: What are the similarities between dilations and the other transformations (translations, rotations, and reflections)?
Draw / write: What is the relationship between scale factor and the size of a dilation?
What strategies can be used to identify the center of a dilation?
How can you determine the scale factor of a dilation given the coordinates of the image points?