.
If the angle measure is x, then the supplementary angle is (x+158) degrees, according to the condition.
It gives you an equation for the angle measure x
x+158 = 180 - x.
Hence,
2x = 180 - 158 = 22.
x = 22/2 = 11 degrees.
Answer. The angle is 11 degrees; the supplementary angle is 180-11 = 169 degrees.
Solved.
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If you want to see many other similar solved problems (tons of them), look into the lesson
- Solved problems on supplementary and complementary angles
in this site.
Also, you have this free of charge online textbook on Geometry
GEOMETRY - YOUR ONLINE TEXTBOOK
in this site.
The referred lesson is 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.