Question

it is given that l is parallel to m to prove angle 1 is supplement to angle 8. Write reasons for the statements. ​

Answer 1

Proof :

In the figure,

The lines l and m are parallel.

So,

∠1 = ∠5 (∵ Alternate interior angles) ...... (1)

And,

∠5 + ∠8 = 180° (Because, it is a straight line)

So,

∠1 + ∠8 = 180° (From the eqn. {1})

As,

The Sum of supplement angles is 180 degrees.

Therefore,

Angles 1 and 8 are supplement with each other.

Hence, Proved.