Respuesta :

Lampa20
In 30-60-90 triangle there is a rule that leg opposite to 30 degree angle is 2x shorter than hypotenuse. That means that shorter leg is 10 feet long.

longer leg we can calculate using Pythagoras theorem.
20^2 = 10^2 + x^2
x^2 = 300
x = √300 = 10√3