The resulting triangle is a right triangle with the third side given:
First, the angle can be solved using the given rise and run of the cable. So,
tan θ = 2 / 5
θ = 15.95°
Next, the lengths b and c can be solved using the solved angle:
tan 15.95 = 1320 / b
b = 3300 ft
The hypotenuse or c can be solved by trigonometric functions or using Pythagorean theorem, using the sine function:
sin 15.95 = 1320 / c
c = 4804 ft