Question 1105524
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Regarding the proof, see the lesson
&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Triangles/Sum-of-the-interior-angles-of-a-triangle.lesson>Sum of the interior angles of a triangle</A>
in this site.


Then

(2x-7) + (x+25) + (3x+12) = 180

6x + 30 = 180

6x = 180-30 = 150  ====>  x = {{{150/6}}} = 25 degrees.


Having this, find the angles on your own.
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