In trapezoid ABCD, sides AB and CD are parallel, angle A = 2*angle D, and angle C = 4*angle B. Find angle A .
Since AB is parallel to CD, then angle A and angle D are supplementary
And D = (1/2)A
So
A + (1/2)A = 180
(3/2)A =180
A = (2/3)(180) = 120°
