In Fig. 8.141, if l || m, then x =

Given that,

l ‖ m and n cuts them

Let,

∠1 = 65^o

∠2 = x

∠3 = 40^o

∠1 = ∠4 = 65^o (Alternate angle) (i)

∠3 + ∠4 + ∠5 = 180^o (Angle sum property)

40^o + 65^o + ∠5 = 180^o

∠5 = 75^o

Now,

∠2 + ∠5 = 180^o (Linear pair)

x + 75^o = 180^o

x = 105^o