AB = 21 DC = 3x AD = y + 7 BC = 2y Quadrilateral ABCD is a parallelogram if both pairs of opposite sides are congruent. Show that quadrilateral ABCD is a parallelogram by finding the lengths of the opposite side pairs. A) 7, 3 B) 14, 7 C) 21, 7 D) 21, 14

Scenario: susan wants to make 2 square flags to sell at a crafts fair. the fabric she wants to buy is 3 meters wide. she doesn't want any fabric left over. what's the least amount of fabric she should buy? question: which equation will susan solve her problem? note: let x represent the length of 1 side of the flag. options: 1) 2x^2 = 4x 2) 8 +2x = 2(4x) 3) 2 * 2 = 4 * 2 4) 4x^2 -2x = 0