Question

if an image of a triangle is congruent to the pre - image, what is the scale factor of the dilation?
○ 0.1
○ \\(\frac{1}{2}\\)
○ 1
○ 10

Explanation:

Step1: Recall congruence and dilation rule

Congruent figures have equal side lengths. Dilation scales side lengths by a factor $k$.

Step2: Set up equality for side lengths

Let pre-image side length = $s$, image side length = $s$. Dilation formula: $s = k \times s$.

Step3: Solve for scale factor $k$

Divide both sides by $s$ ($s
eq 0$): $k = \frac{s}{s} = 1$.

Answer:

1