I am brain dead on this one and I know its faily simple but its been a while since I've done one of these... please help!

An airplane traveling at 240mph is descending at an angle of 12degrees. How many miles will the plane descend in 8 minutes?

At 240 mph the plane will travel 32 miles in 8 minutes.

On the vertical, it desends 32sin(12) miles.