I get how to solve for angle A but wht about angle B? PLS PROVIDE AN EXPLAINATION

Since the shape has 4 sides, all of the angles add up to 360 degrees. We know that two of the angles are 72 degrees, and B & D are equal to each other. Multiply 72 by 2 to get 144, then subtract 360 - 144 to get 216, which is B and D added together. Divide 216 by 2 and your answer is 108!

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