trig
posted by joey .
A tree growing on a hillside casts a 121foot shadow straight down
the hill. Find the height of the tree (in feet) if the slope of the hill is 8 degrees
and the angle of elevation of the sun from the horizontal is 50degrees.

see whether you can figure how I developed the required formula for the height h of the tree:
h = 121(cos8°tan50°  sin8°) = 126 ft
Draw a diagram and figure out some of the distances.