We know the following:
-the angle is 61 degrees
-one side is 12
What we need to look for:
-a, the hypotenuse
What to do:
Find what trig ratio to use. The side of 12 is opposite the angle, and a (as I said), is the hypotenuse. So what we need to do is use cosine, which is opp/adj.
cos(61°) = 12/a
First we need to find the cosine of 61°. Since the answer requires two Demical places, I will use 0.48. (Although the actual answer is 0.484806…)
0.48 = 12/a
Now multiply by a.
0.48a = 12
Now divide by 0.48.
a = 25.
I will also use the actual value then round at the end.
cos(61) * a = 12
a = 12/cos(61)
a=24.75
Feel free to use either answer, but I’d prefer the second one for better accuracy.