Okay so the small triangle has sides that are 3 units, 4 units and 5 units long
the larger triangle has sides that are 6 units, 8 units and 10 units long so using this information we can see that the larger triangle is twice the size of the small triangle.
Hope this helps :)
The answer is 17, steps are in photo below.
I uploaded the answer to a file hosting. Here's link:
tinyurl.com/wpazsebu
