We are given an angle of 60° and a side of 15 cm.
We are given the opposite and is looking for the hypotenuse so we will use the sine ratio to find x.
sin = opp/hyp
hyp = 15 / sin 60
hyp = 17.32...
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We can also use the tangent ratio to find the adjecent and then use pythagorean to find x.
tan = opp/adj
adj = 15 / tan 60
adj = 8.660.....
8.660....² + 15² = 300²
since the square root of 300 is an irrational number, we have to turn it into a mixed radical.
The answer would be the top one.