math HELP!
posted by Kat on .
nobody has answered yet and this is the only question I need :(
If angle A=30* and side b=4.0 km, how do I find side c?
I know that this is a 306090 triangle but I don't know how to find the hypotenuse. please help!

Since angle B is 60 degrees, and A is less (30 degrees) the law of sines says that the length of side a is less than that of side b. The length of side c is given by the lasw of sines:
c/sin 90 = c = b/sin60
c = 4.0/0.866 = 4.619 km