In Fig. 5.64, fin

∠ VUF + ∠ TUV = 180⁰

∠ TUV = 180⁰-123⁰ = 57⁰

∠ TUV = ∠UVH

So they form alternate interior pairs

Hence EF||GH

∠UVH≠∠ VQP

Hence PK is not parallel to EF and GH

∠ VUF≠∠RSV

Hence AB is not parallel to CD as they don’t form corresponding pairs.

EF||GH