9514 1404 393
Answer:
x = 102
Explanation:
Isosceles triangles have equal angles opposite equal sides. There are two 39° angles in this triangle (opposite the 3.3 sides), so the third one is ...
x° = 180° -2(39°)
x° = 102°
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Additional comment
The triangle is "overspecified", meaning more measures are provided than are necessary to completely describe the triangle. As is often the case in such situations, the measures provided are sufficiently inconsistent that two different "right" answers are possible, depending on how you work the problem. The first attachment shows the solution above.
The second attachment shows the solution you might get by using the Law of Cosines. Note that x=101 in this case.