In Fig. 5.30, lin A. ∠1 = ∠3

B. ∠2 = ∠4

C. ∠6 = ∠7

D. ∠4 = ∠8

According to this figure

∠ 1 = ∠ 3 (Corresponding angles)

∠2 = ∠4 (Corresponding angles)

∠6 = ∠5 (Vertically Opposite angle)

∠5 = ∠7 (Corresponding angles)

So we can say

∠6 = ∠7

∠2 and ∠8 are supplementary pair

Since ∠2 = ∠4

So ∠4 and ∠8 are also supplementary pair

Hence ∠4≠∠8