Erika is writing a coordinate proof to show that the diagonals of a rectangle are congruent. she begins by assigning coordinates to the vertices of a rectangle as shown. which sentence describes what erika should do to prove that the diagonals of the rectangle are congruent? show that the slope of km¯¯¯¯¯¯¯ is ba and the slope of jl¯¯¯¯¯ is −ba. show that the diagonals intersect at (a2, b2) . show that jl=km=a2+b2−−−−−−√. show that jl¯¯¯¯¯ and km¯¯¯¯¯¯¯ have the same midpoint.