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Worth 30 points! in this diagram, both polygons are regular. what is the value, in degrees, of the sum of the measures of angles abc and abd?

21 type the correct answer in each box. if necessary, round your answers to the nearest hundredth the vertices of abc are a(2,8), b(16, 2), and c(6,2). the perimeter of abc is units, and its area is square units

Similarly fie each expression 18,19,20