Answer:
84.5
Explanation:
Use trig functions to find x. Trig functions are special relationships which exits between the sides of right triangles. Since you need to find x the hypotenuse and you have the adjacent side to 77 degree angle use cosine.
Cos 77 = 19/x
0.22495 = 19/x
19/0.22495 = x
84.5 = x