Answer
BS=24ft
Work Step by Step
Given:
support system of a bridge which has
AC=6ft
m$\angle$ABC=28$^{\circ}$
AC=CD=VT=TR= 6ft because they are corresponding angles of congruent triangles
also DV=AD
AD=AC+CD
AD=6ft +6ft
AD=12ft
DV=AD=12ft
BS=CD+DV+VT
BS=6+12+6
BS=24ft
therefore,
m$\angle$ABD=m$\angle$ABC+m$\angle$CBD
m$\angle$ABD=28$^{\circ}$+28$^{\circ}$
m$\angle$ABD=56$^{\circ}$