Question

help!

Answer 1

@reemii

Answer 2

Remember the Theorems with the alternating angles. You have to reach the point where you have know that alternating angles (interior or exterior) are equal. Then the conclusion will be "then the lines are parallel".

What can you say around the angle 2, for example 2<->1, 2<->4, 2<->3 ?

Answer 3

angle2 = angle3 (always)
angle1 and angle2 are supplementary (always true)
angle2 and angle4 are supplementary (always true)

Answer 4

The objective is to show that 3 and 6 are equal.

angle2 =angle3, angle3 supplementary with angle5, .. next?

Answer 5

What is the property between angles 5 and 6 ?

Answer 6

supplementary

Answer 7

Yes, so what about 3 and 6?

Answer 8

supplementary

Answer 9

oops..
"3 and 5 suppl." means : angle3 + angle5 = 180°
"5 and 6 suppl." means : angle5 + angle6 = 180°

-> this means angle3 = angle6

Answer 10

congruent i meant

Answer 11

yes

Answer 12

So: the steps are:

5<->6 :suppl (this becomes the first step, must come before the conclusion ;) )
2<->3 : equal
3<->5 : suppl (Given)
Theorem of alternating angles =>l // m