Given:
One of the angle of a triangle is 104°.
The objective is to find the missing angle x.
If two sides of a triangle are equal, then it is an isosceles triangle.
In an isosceles triangle, the angle formed by the equal sides is also equal.
Then, the value of angle x can be calculated angle sum property of triangle.
[tex]\begin{gathered} x+x+104\degree=180\degree \\ 2x+104\degree=180\degree \\ 2x=180\degree-104\degree \\ 2x=76\degree \\ x=\frac{76}{2} \\ x=38\degree \end{gathered}[/tex]
Hence, option (A) is the correct answer.
