Two quadrilaterals are similar if corresponding sides taken in the same
sequence (even if clockwise for one quadriateral and counterclockwise for the
other) are proportional and corresponding angles taken in the same
sequence are equal in measure.
If the quadrilaterals JKLM and PQRS are similar, then
[tex] \dfrac{JK}{PQ} = \dfrac{KL}{QR} = \dfrac{LM}{RS} = \dfrac{JM}{PS} [/tex].
Hence
[tex] \dfrac{4}{QR} = \dfrac{3}{4.8} = \dfrac{5}{8} = \dfrac{3}{4.8} [/tex] and
[tex]QR= \dfrac{4\cdot 8}{5} =6.4[/tex].
