6.8 **SUMMARY:**

If a transversal intersects two parallel lines then

( i ) corresponding angles are equal

( ii ) alternate interior angles are equal

( iii ) each pair of interior angles on the same side of the transversal is supplementary

If a transversal intersects two parallel lines then each pair

of alternate interior angles are equal

The alternate interior angles are

a ) ∠ 4 and ∠ 6 b ) ∠ 3 and ∠ 5

These angles will be equal to each other if

Lines l and m are parallel to each other

If line l ∥ m then ∠ 4 = ∠ 6 and ∠ 3 = ∠ 5 If a transversal intersects two parallel lines then each pair

of interior angles on the same side of the transversal is supplementary

The interior angles on the same side of the transversal are

( i ) ∠ 4 and ∠ 5 ( ii ) ∠ 3 and ∠ 6

These angles will be supplementary ( equal to 180° )

if the lines are parallel