If two pentagons are similar, then their sides are proportional. To find PT, we'll need to set up a proportion.
AE / PT = AB / PQ
---There are many ways to set up this proportion, it just depends on what side lengths you have and ensuring that they match up on both shapes.
6 / x = 5 / 12.5
5x = 75
x = 15
Length of PT = 15 cm
Option C
Hope this helps!