Hi, I need help with one question, I'm completely confused, so please show me how to work it out. Thanks in advance.

From point D, the angle of elevation of a cliff top (F) is 42 degrees. After walking 85m along a street inclined at 11 degrees (D to E), the angle of elevation from point E is 55 degrees.Question:

Work out angles FDE and DEF.

Find the height of the cliff.