#1**0 **

Let's finish labelling the vertices of the triangle: let C be the vertex at angle(x) and let D be the upper vertex.

Arc(BC) = 160^{o} because it is double the angle.

Arc(CD) = arc(BC) because their chords are congruent. Therefore, arc(CD) = 160^{o}.

This means arc(BD) = 360^{o} - 160^{o} - 160^{o} = 40^{o}.

Angle(x) is one-half the arc it intercepts, so it is 20^{o}.

geno3141 Jul 24, 2020