Question

What is the m/ABD in the figure below?
A
D
71°
C
B

Answer 1

Angle ABD is 19 degrees.

Triangle ABC is an isosceles - - - two sides are the same.

Angle ABC is split equally - - - angle ABD is the same as angle DBC.

Angle DAB is the same as angle DCB.

Angle ADB is 90.

So:

71 + 90 + angle ABD = 180

161 + angle ABD = 180

That makes ABD = 19 degrees.