Consider the diagram and proof below.Given: WXYZ is a parallelogram, ZX ≅ WYProve: WXYZ is a rectangle Statement Reason1.WXYZ is a ▱; ZX ≅ WY1.given2.ZY ≅ WX2.opp. sides of ▱ are ≅3.YX ≅ YX3.reflexive4.△ZYX ≅ △WXY4.SSS ≅ thm.5.∠ZYX ≅ ∠WXY5.CPCTC6.m∠ZYX ≅ m∠WXY6.def. of ≅7.m∠ZYX + m∠WXY = 180°7.?8.m∠ZYX + m∠ZYX = 180°8.substitution9.2(m∠ZYX) = 180°9.simplification10.m∠ZYX = 90°10.div. prop. of equality11.WXYZ is a rectangle11.rectangle ∠ thm.What is the missing reason in Step 7?