The tops of two vertical poles of heights 20 m and 14 m, standing on level ground, are joined by a straight wire that makes an angle of 30° with the horizontal. The length of the wire is:

The wire is the hypotenuse of a right triangle whose vertical leg is the difference in heights, 20 − 14 = 6 m. So sin30° = 6/L, giving L = 6/(1/2) = 12 m. Using the horizontal leg instead (6·cot30°) gives 6√3 ≈ 10.39 m.