Question

~please only answer if you know for sure~
-Thank you-

Answer 1

DF and AC are similar

and

BC and EF are similar sides

So make a proportion


`\sf{ (AC)/(DF) = (BC)/(EF) }`

Plug in the numbers


`\sf{ (9)/(DF) = (15)/(25) }`

Cross multiply


`\sf{DF * 15 = 9 * 25}`

Isolate DF and simplify it


`\sf{DF = 15}`

And so your final answer is


`\boxed{\bf{15 ~centimeters}}`