Answer
Length of the rafter $= 14.5 ft$
Work Step by Step
The length of the rafter is the hypotenuse of one of the 2 smaller triangles formed by dividing the span in half and adding the extra segment outside of the rise.
So, we have:
length of the rafter $= \sqrt {(5ft)^{2} + (12ft)^{2}} + 1.5ft = 14.5ft$
