Question

estimation without doing calculations, use side de and side de to estimate the scale factor for the dilation shown. then use two corresponding sides to find the scale factor.
side de looks about 3 times longer than side de.
the scale factor for this dilation is
(simplify your answer.)

Explanation:

Step1: Identify lengths of DE, D'E'

From the graph, $DE = 3$ units, $D'E' = 9$ units.

Step2: Calculate scale factor

Scale factor = $\frac{\text{Length of image side}}{\text{Length of pre-image side}}$
$\text{Scale factor} = \frac{D'E'}{DE} = \frac{9}{3}$

Step3: Simplify the fraction

$\frac{9}{3} = 3$

Answer:

Side D'E' looks about 3 times longer than side DE.
The scale factor for this dilation is 3.