Answer:
I have made it in above picture hope it helps
5
you use the formula a^2+b^2=c^2
a=3, b=4
3*3=9 and 4*4=16
16+9=25
square root of 25 is 5.
5 is the answer
Applying a dilation centered at the origin with scale factor
has the effect of multiplying both coordinates of a point by
:

So, in your case, the coordinates of the points double:

I'm pretty sure it would have to be 155. Considering a flat line has an angle of 180 and if you subtract 180 from 25 you get 155.