Question

Triangles ABC and PQR are similar. What is the length of PQ?

• A. 9
• B. 10.5
• C. 13
• D. 15

Answer 1

The correct option is B 10.5

First find the scale factor:
Since AC = 12 and PR = 18, the scale factor is found by dividing PR by AC
Scale factor = $\frac{18}{12}=1.5$
(That means that the second triangle is 1.5 times as large as the first)
Now use the same scale factor to find the length of PQ:
PQ = 1.5 x 7 = 10.5