Look at angle c, and then look at the other measures and sides. Which sides are shown with their values? The hypotenuse, opposite side, and adjacent side are shown, with their values, so let's choose which way we're going to do this (sine, cosine, tangent). Let's pick tangent, just because :)
tan c° = opposite side / adjacent
So, plug in the values.
Opposite side = 28
Adjacent = 45
tan c° = 28/45
Divide 28 from 45.
tan c° = 0.6222
Your teacher may have given you the Table of Trigonometric Ratios. Go onto the tangent side of the paper, and look through the numbers. Which number is closest to 0.6222?
32° is!
So :
c = 32°
However, because this is rounded, we must look at the answer choices and see which one is closest to 32°.
31.9° is closest to 32°, so 31.9° is your answer.
~Hope I helped!~
