Question

In the given figure, is 'l parallel
to 'm' ? Justify​

Answer 1

Proof:-

Suppose l ║ m, Then n is transversal.

∵ If two parallel lines intersected by transversal then,

Consecutive Interior angles are Supplementary.

∴ 126° + 44° ≠ 180°

⇒ 170° ≠ 180°

Here, Consecutive Interior angles are not Supplementary.

Hence, l ∦ m, l is not parallel to m.

Some Important Terms:-

• If two parallel lines intersected by a transversal then:-

1. Their Alternate interior angles are equal.
2. Their Corresponding angles are equal.
3. Sum of Consecutive interior angles are 180°.
4. Their Alternate exterior angels are equal.
5. Vertically Opposite angles are equal.