Respuesta :

Law of cosines.

Cos(angle) = Adjacent Leg / Hypotenuse

Cos(60) = 20 / x

X = 20/cos(60)

x = 40 ft.

Answer:

40

Step-by-step explanation:

You have a 30-60-90 right triangle. The hypotenuse is twice the length of the short leg.

BC = 2 * 20 = 40