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The sum of interior angles of a hexagon is (6-2)*180° = 4*180° = 720°.
Because the sum of interior angles of ANY n-sided polygon is (n-2)*180°.
In your case it means that
x + x + x + 115 + 85 + 130 = 720 degrees, or
3x + 330 = 720
3x = 720 - 330 = 390 ====> x = = 130°.
Answer. The measure of each of the three congruent angles is 130°.
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In this site, there is a bunch of lessons with solved problems on angles of triangles, parallelograms, quadrilaterals and polygons
- Solved problems on angles of a triangle
- Solved problems on angles of a parallelogram
- Solved problems on angles of a quadrilateral
- Solved problems on angles of a polygon
- Solved problems on missed angle of a polygon
- Solved problems on angles of a regular polygon
Read them and become an expert in the area.
Also, you have this free of charge online textbook on Geometry
GEOMETRY - YOUR ONLINE TEXTBOOK
in this site.
The referred lessons are the part of this online textbook under the topic "Finding angles of triangles, parallelograms and rectangles".
Save the link to this online textbook together with its description
Free of charge online textbook in GEOMETRY
https://www.algebra.com/algebra/homework/Triangles/GEOMETRY-your-online-textbook.lesson
to your archive and use it when it is needed.