Ok. I missed class today so didnt quite get the lesson via math tutorial.

The question is:

When a 757 passenger jet begins its descent to the Ronald Reagan International Airport in Dc, it is 3900 ft from the ground. its angle od descent is 6 degrees.

a. what is the plane's ground distance to the airport?

b. how far must the plane fly to reach the runway?

idk how to do it from the tutorial this is what i did....

cos 6 =3900

6 = 3921.5

is that how im suppose to folllow thru and do?

please any suggestions