In Fig. 8.142, if lines l and m are parallel, then the value of x is

Given that,

l ‖ m and n cuts them

Let,

∠1 = x

∠2 = 90^o

∠3 = 125^o

∠3 + ∠5 = 180^o (Linear pair)

125^o + ∠5 = 180^o

∠5 = 55^o (i)

∠4 = 90^o (ii)

Now,

∠1 + ∠4 + ∠5 = 180^o (Angle sum property)

x + 90^o + 55^o = 180^o

x = 35^o