Complete the coordinate proof of the theorem. given: a b c d is a parallelogram. prove: the diagonals of a b c d bisect each other. art: a parallelogram is graphed on a coordinate plane. the horizontal x-axis and vertical y-axis are solid. the vertex labeled as a lies on begin ordered pair 0 comma 0 end ordered pair. the vertex labeled as b lies on begin ordered pair a comma 0 end ordered pair. the vertex labeled as d lies on begin ordered pair c comma b end ordered pair. the vertex c is unlabeled. diagonals a c and b d are drawn by a dotted lines. enter your answers in the boxes. the coordinates of parallelogram abcd are a(0, 0) , b(a, 0) , c( , ), and d(c, b) . the coordinates of the midpoint of ac¯¯¯¯¯ are ( , b2 ). the coordinates of the midpoint of bd¯¯¯¯¯ are ( a+c2 , ). the midpoints of the diagonals have the same coordinates. therefore, ac¯¯¯¯¯ and bd¯¯¯¯¯ bisect each other.