Math Forum :: View topic – Geometric problem

Refer to the above figure, it is given that angle ABF = 20 deg, angle FBC = 60 deg, angle BCF = 50 deg and angle FCA = 30 deg. Find the value of angle FDE. Using trigonometric method, the value was found to be 30 degrees. Just want to know if there is any other method. ( geometrical method prefered. )