A quadrilateral has the following vertices: (4, 4), (6,6), (8, 4), (6, 2). After dilation, the new quadrilateral has the following vertices: (3, 3), (4.5, 4.5), (6, 3), (4.5, 1.5). What scale factor was used to dilate the quadrilateral? (1 point)

1 answer

To find the scale factor for the dilation of the quadrilateral, we can compare the corresponding vertices of the original quadrilateral and the dilated quadrilateral.

The original vertices are:

  1. \( A(4, 4) \)
  2. \( B(6, 6) \)
  3. \( C(8, 4) \)
  4. \( D(6, 2) \)

The dilated vertices are:

  1. \( A'(3, 3) \)
  2. \( B'(4.5, 4.5) \)
  3. \( C'(6, 3) \)
  4. \( D'(4.5, 1.5) \)

We can use any pair of corresponding vertices to find the scale factor. Let's use points A and A':

The formula for dilation, if the scale factor is \( k \), is: \[ A' = (k \cdot x_A, k \cdot y_A) \]

For point \( A \): \[ A' = (3, 3), \quad A = (4, 4) \]

Setting up the equations for the scale factor \( k \): \[ 3 = k \cdot 4 \quad (1) \] \[ 3 = k \cdot 4 \quad (2) \]

From equation (1): \[ k = \frac{3}{4} \]

Now, let's check this scale factor with point B and B':

For point \( B \): \[ B' = (4.5, 4.5), \quad B = (6, 6) \]

Setting up the equations again for the scale factor \( k \): \[ 4.5 = k \cdot 6 \quad (3) \] \[ 4.5 = k \cdot 6 \quad (4) \]

From equation (3): \[ k = \frac{4.5}{6} = \frac{3}{4} \]

We'll check with point C to see if it remains consistent:

For point \( C \): \[ C' = (6, 3), \quad C = (8, 4) \]

Setting up the equations: \[ 6 = k \cdot 8 \quad (5) \] \[ 3 = k \cdot 4 \quad (6) \]

From equation (5): \[ k = \frac{6}{8} = \frac{3}{4} \]

Finally, checking with point D:

For point \( D \): \[ D' = (4.5, 1.5), \quad D = (6, 2) \]

Setting up the equations: \[ 4.5 = k \cdot 6 \quad (7) \] \[ 1.5 = k \cdot 2 \quad (8) \]

From equation (7): \[ k = \frac{4.5}{6} = \frac{3}{4} \] From equation (8): \[ k = \frac{1.5}{2} = \frac{3}{4} \]

All pairs of corresponding vertices give the same scale factor. Therefore, the scale factor used to dilate the quadrilateral is:

\[ \boxed{\frac{3}{4}} \]