Question

triangle rst is dilated by a scale factor of 3 to create triangle rst. if the area of triangle rst is 12 square inches, what is the area of triangle rst?
a 72 square inches
b 4 square inches
c 36 square inches
d 108 square inches

Explanation:

Step1: Find area scale factor

When a figure is dilated by a scale factor $k$, the area scales by $k^2$. Here $k=3$, so area scale factor is $3^2=9$.

Step2: Calculate new area

Multiply original area by scale factor.
$\text{Area of R'S'T'} = 12 \times 9$

Answer:

D. 108 square inches