Answer:
25
Explanation:
Since triangle DBC is isosceles, angles DBC and DCB must be congruent. Angle BDC is 40 so the sum of the measures of the aforementioned angles must be 180 - 40 = 140; divide that by two and you get that the measure of angle DBC is 70. Angles DBC and ABD are supplementary, as they lie on a straight line, so we can deduce the measure of angle DBA is 180 - 70 = 110. The measure of angle DAB is 180 minus the measures of angle DBA and ADB, we figured out angle DBA is 110 degrees and the problem tells us angle ADB is 45 degrees, so we can subtract to get the measure of angle DAB to be 180 - (110 + 45) = 25.