Question

if △pqr ~ △stu, what is the scale factor of △pqr to △stu? a. $\frac{1}{5}$ b. $\frac{1}{4}$ c. 4 d. 5

Explanation:

Step1: Recall scale - factor formula

The scale factor of $\triangle PQR$ to $\triangle STU$ is the ratio of the corresponding side lengths of $\triangle PQR$ to $\triangle STU$.

Step2: Identify corresponding sides

Let's assume the side of length 20 in $\triangle PQR$ corresponds to the side of length 4 in $\triangle STU$.

Step3: Calculate the scale factor

The scale factor $k=\frac{\text{side in }\triangle PQR}{\text{corresponding side in }\triangle STU}=\frac{20}{4}=5$.

Answer:

D. 5