Answer:
Base angles in an isosceles triangle are equal.
Angle in triangle adds to 180
Triangle BADB
180- 72=108
108/2=54
Angle BAB And BDA is 54
Angle on straight lines adds to 180
180-54=126
Angle BDC is 126
180-126=54
54/2 =27
Angle DBC and DCB is 27
Now forget line BD exist, creating triangle ABCA and with the values you've found, use it to see if all angles adds up to 180.
DBC is 27 adds to 72. Add this to angle BAD (54) and BCD (27)
27 +72=99
54+27=81
99+81=180
