Unit 6 · Similarity and Dilations

6.2Dilations in the Coordinate Plane

Quick Answer

A dilation with center (0,0) and scale factor k maps (x,y) to (kx,ky). If k>1 the image is an enlargement; if 0<k<1 it is a reduction. Dilations preserve angle measures but not side lengths.

Essential Question

How does a dilation transform a figure while preserving its shape but changing its size?

Learning Goals

  • 1Define dilation, center of dilation, and scale factor.
  • 2Apply dilation rules in the coordinate plane.
  • 3Distinguish enlargements from reductions.
  • 4Verify that dilations preserve angle measures.

Key Vocabulary

Dilation

A transformation that enlarges or reduces a figure by a scale factor relative to a center point.

Center of dilation

The fixed point from which all points are scaled.

Enlargement

A dilation with scale factor k > 1.

Reduction

A dilation with scale factor 0 < k < 1.

Full lesson content coming soon

Worked examples, guided practice problems, a workbook, quiz, and downloadable PDF resources will be added to this lesson in Phase 2. The learning goals and vocabulary above reflect the complete lesson scope.