Using relations in a right triangle, it is found that the length of the zip line is of about 63.9 ft.
The relations in a right triangle are given as follows:
In this problem, the hypotenuse is the length of the line, considering that the base of 60 ft is adjacent to the angle of 20º, hence:
[tex]\cos{20^\circ} = \frac{60}{l}[/tex]
[tex]l = \frac{60}{\cos{20^\circ}}[/tex]
[tex]l = 63.9[/tex]
The length of the zip line is of about 63.9 ft.
More can be learned about the relations in a right triangle at https://brainly.com/question/18090623