Question

if △abc ~ △def, what is the scale factor of △abc to △def? a. $\frac{1}{10}$ b. 2 c. 10 d. $\frac{1}{2}$

Explanation:

Step1: Identify corresponding sides

Corresponding sides of similar triangles are in proportion. Let's take side $BC = 20$ and side $EF=10$.

Step2: Calculate scale - factor

The scale factor of $\triangle ABC$ to $\triangle DEF$ is the ratio of the lengths of corresponding sides. Scale factor $k=\frac{BC}{EF}$. Substitute $BC = 20$ and $EF = 10$ into the formula: $k=\frac{20}{10}=2$.

Answer:

B. 2