Answer
$\angle$BAD=37$^{\circ}$
Work Step by Step
Given:
A roof truss with AB=8 and $\angle$HAF=37$^{\circ}$
as we all know in a roof truss opposite triangles are always congruent that means
$\triangle$ABD is congruent to $\triangle$AFH
therefore,
$\angle$HAF=$\angle$BAD=37$^{\circ}$