help geometry

In triangle ABC, the measure of angle A is x degrees, the measure of angle B is 2x degrees and the measure of angle C is 6x degrees. What is the value of x? Express your answer as a decimal to the nearest tenth.    

A = x     B = 2x     C = 6x    

A + B + C  =  180^o    

x + 2x + 6x  =  180^o    

              9x  =  180^o     —>>     x = 20.0^o    

_.