What Is Dilation in Geometry?

In geometry, dilation is the resizing of an object. With dilation, the angles remain the same, but the distance between points increases or decreases by a common scale factor.

In dilations, lines that are parallel in the original figure remain parallel in the resized object. Each point that was on the original line moves to the dilated line, including the midpoint. The dilated figure retains the same order for labels as the original figure. Artists use dilations when painting landscapes in perspective. They reduce the size of each object by the same amount while keeping the angles the same. Maps are dilations that use a scale factor to condense information onto easy-to-handle sheets of paper.