Question

One triangle has side lengths 3,5, and 6. A similar triangle has side lengths 18, 15 and 9. Which of the following ratios is the scale factor of the triangles?

A 1/6
B 1/3
C 1/5
D 2/3

The answer is given as B, but I don't understand why or how to get that. Please help.

Answer 1

longest sides: 18/6 = 3
check
15/5 = 3 and 9/3 = 3
so
1/3

Answer 2

Thank you!