Polygon D has been dilated to create polygon D′.

Polygon D with top and bottom sides labeled 8 and left and right sides labeled 9.5. Polygon D prime with top and bottom sides labeled 3.2 and left and right sides labeled 3.8.

Determine the scale factor used to create the image.
Scale factor of 0.4
Scale factor of 2.5
Scale factor of 0.2
Scale factor of 1.2

1 answer

To determine the scale factor used to create polygon D′ from polygon D, you can use the lengths of corresponding sides of the two polygons.

For the top/bottom sides:

  • Length of side in polygon D = 8
  • Length of corresponding side in polygon D′ = 3.2

The scale factor is calculated as: \[ \text{Scale factor} = \frac{\text{Length of D′}}{\text{Length of D}} = \frac{3.2}{8} = 0.4 \]

Now, let's check the left/right sides to ensure consistency:

  • Length of side in polygon D = 9.5
  • Length of corresponding side in polygon D′ = 3.8

Calculating the scale factor for the left/right sides: \[ \text{Scale factor} = \frac{3.8}{9.5} \] To simplify this, we can divide both numbers by their greatest common divisor: \[ \frac{3.8}{9.5} = \frac{3.8 \div 3.8}{9.5 \div 3.8} = \frac{1}{2.5} = 0.4 \]

Since both corresponding sides yield the same scale factor of 0.4, we can confirm that the scale factor used to create polygon D′ from polygon D is:

Scale factor of 0.4.