Grade 8 Math · Geometry

Dilate figures on coordinate plane

Dilate figures on coordinate plane.

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What you’ll learn

Dilate figures on coordinate plane.

Key idea

A dilation about the origin multiplies both coordinates by the same positive factor; it is not a vector addition.

Both coordinates share one scale; squared pairwise distances scale by its square.

Worked example

Enter the exact value or ordered values in the format requested below.

Read image I of P after dilation factor 1/2 centered at origin. Enter image coordinate.

-6-4-202466420-2-4-6IPxy

Marked coordinates: I=(-1, -1); P=(-2, -2).

  1. Origin-centered dilation multiplies each coordinate by 1/2.
  2. Vertices [(-2, -2), (0, -2), (-2, 0)] map to [(-1, -1), (0, -1), (-1, 0)]; every pairwise length scales by 1/2, while corresponding angles are preserved.

Answer: (-1,-1)

Quick Check

Relate the graph used in 'Dilate figures on coordinate plane' to an equation, table, transformation, or verbal description.

Connect mapping table [((4, -2), (8, -4)), ((6, -2), (12, -4)), ((4, 0), (8, 0))] and image graph to a common dilation rule.

-6-4-2024686420-2-4-6PIxy

Marked coordinates: P=(4, -2); I=(8, -4).

Choose one answer

Show a hint

Locate image I using horizontal-then-vertical axis labels.