Can the property of alternate angles be applied even to non-parallel lines or only for parallel lines?

My elder brother says that it can be applied even for non-parallel lines. But I say that it can be applied only for parallel lines (the property of alternate angles). Who is correct???

Can the property of alternate angles be applied even to non-parallel lines or only for parallel lines?

3 Replies to “Can the property of alternate angles be applied even to non-parallel lines or only for parallel lines?”

1. Prudhavi K says:

Hi,
My friend you are wrong . Alternate angles are equal properties are applicable to non parellel lines also. I”ll Give th proof why they can be applied even to non parellel lines.

PROOF: Take two lines PQ andRS . let them intersect at a point say “N” . Let angle PNS be “x”. the as in a straight line sum of angle must be complementery and hence angle PNR must be “pi–x” and then applying the same rule for the other line we get angle QNR is also “x” and hence this property is proved..

Please excuse me Because i can’t draw figure..

2. munch says:

yes it is applicable for non parallel lines also .the best example is alternate angles segment theorem

3. Sana says:

it is applied only in case of parallel lines