Use the given vertices to graph BCD and its image after a dilation centered at the origin with scale factor k=-1/5

B(-5, -10), C( -10, 15), D(0, 5)

1 answer

To graph triangle BCD and its dilated image after applying the dilation centered at the origin with a scale factor of \( k = -\frac{1}{5} \), we can follow these steps:

Step 1: Plot the Original Triangle BCD

  1. Plot the vertices:

    • B (-5, -10): Left 5 units and down 10 units.
    • C (-10, 15): Left 10 units and up 15 units.
    • D (0, 5): No movement along the x-axis and up 5 units.
  2. Draw the triangle: Connect the points B, C, and D to form triangle BCD.

Step 2: Perform the Dilation

The formula for dilation centered at the origin with a scale factor \( k \) is: \[ (x', y') = (k \cdot x, k \cdot y) \]

For the scale factor \( k = -\frac{1}{5} \), we will apply this to each vertex.

Calculate the new coordinates:

  1. For vertex B (-5, -10): \[ B' = \left(-\frac{1}{5} \cdot -5, -\frac{1}{5} \cdot -10\right) = \left(1, 2\right) \]

  2. For vertex C (-10, 15): \[ C' = \left(-\frac{1}{5} \cdot -10, -\frac{1}{5} \cdot 15\right) = \left(2, -3\right) \]

  3. For vertex D (0, 5): \[ D' = \left(-\frac{1}{5} \cdot 0, -\frac{1}{5} \cdot 5\right) = (0, -1) \]

Step 3: Plot the Dilated Image B'C'D'

  1. Plot the new vertices:

    • B' (1, 2): Right 1 unit and up 2 units.
    • C' (2, -3): Right 2 units and down 3 units.
    • D' (0, -1): No movement along the x-axis and down 1 unit.
  2. Draw the new triangle: Connect the points B', C', and D' to form triangle B'C'D'.

Final Step: Graph Both Triangles

Ensure both triangles BCD and B'C'D' are visible. The original triangle BCD should be in one color (e.g., blue) and its image B'C'D' in a different color (e.g., red).

This illustrates how the points have been dilated and provides a clear comparison between the original and the transformed shapes.