Will give brainliest to correct answer.
2 answers:
Use Pythagorean's Theorem to solve for c. 
. We will simplify the right side by squaring both terms. 
which simplifies even further to 
. In that polynomial, the leading coefficient, 4, is a perfect square, and so is the constant at the end, 9. So that polynomial is the sum of perfect squares. It will break down like this: 
so then taking the square root of both sides gives us that c = 2x + 3, choice on the top right.
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Check the picture below.
notice that 146° is sitting on a flat-line, and thus it has a sibling linear angle, namely 34°.
now, recalling that a triangle has a sum of 180° for all interior angles, the missing one is 126°, and incidentally that is a corresponding angle with "c".
