1. parallel lines and transversals

Lines l1 and l2 intersect each other and 3 parallel lines, l3, l4, and l5, at the points shown below. The ratio of the perimeter of triangle ABC to the perimeter of triangle AFG is 1:3. The ratio of DE to FG is 2:3. What is the ratio of AC to CE?

I know that answer is 1:1 but I'm not sure how to prove it..

2. "I'm not sure how to prove it.." You're not sure or you don't know?

Indication: Use The Fundamental Theorem of Similarity and/ or Thales' Theorem.

3. So I looked both of those up and it's still unclear how to use them for this proof.. so how do you prove it?

4. "So I looked both of those up and it's still unclear how to use them for this proof" ... in ten minutes, well, yeah, obviously it's unclear.

What exactly don't you understand?

5. I don't understand how to show the result that those lengths are 1:1, so how do you do it??

6. "Indication: Use The Fundamental Theorem of Similarity and/ or Thales' Theorem." Remember that?

"The ratio of the perimeter of triangle ABC to the perimeter of triangle AFG is 1:3. The ratio of DE to FG is 2:3." This is what you know, use it and The Fundamental Theorem of Similarity for two conveniently chosen triangles. After that thinghs should be clear.

7. Yeah I know about similarity, what I don't know is how to relate it to this problem? Anyone else wanna help take a crack at this?

8. Sooo... you're waiting for someone to solve your problem and refuse to think, nice, very nice -_-

"how to relate it to this problem" You sure know that theorems?

"Lines l1 and l2 intersect each other and 3 parallel lines, l3, l4, and l5, at the points shown below."

9. Simply restating the problem isn't helping and just because I don't see what to do, doesn't mean I'm not thinking about it. So is there anyone who does?

10. parallel lines and transversals

Hi Sarahh.
Draw a triangle ABC with a base BC Mark the midpoints of AB and AC m and n. Draw a line mn. Measure the perimeters of the two triangles . Compare all ratios of the sides of both triangles. Then repeat the procedure with your diagram but with the given perimeters or other info

bjh