Let's start from the area formula. The area can be found with: A = 0.5bh, where b is the base and h is the height.
Well, let's just plug in the values and solve for h instead:
127.5 =0.5(17)h
127.5 = 8.5h
h = 15
I got the height of this triangle is 15, but it is always helpful to double check work. Hope this helps!