Question

Triangle trouble. Please Help.

Answer 1

Prove that a line that divides two sides of a triangle proportionally is parallel to the third side. Be sure to create and name the appropriate geometric figures.

Answer 2

I'm not looking for direct answers, I'd just appreciate a nudge or two.

Answer 3

Oh?

Answer 4

A double negation, yeah? Isn't that basically indirectly proving?

Answer 5

Wouldn't that rely on the lines being parallel?

Answer 6

Oh, I see what you mean

Answer 7

Hmmm...

Answer 8

where is the question?

Answer 9

Sorry,

Prove that a line that divides two sides of a triangle proportionally is parallel to the third side. Be sure to create and name the appropriate geometric figures.

Answer 10

It's not a question, it's a command. That's all that's given. I think I'm proving the converse of the triangle proportionality theorem.

Answer 11

Ooh I could probably say the triangles are similar, thus having congruent angles, then say by extension or by that they're exterior or interior angles or whatever that they're parallel.

Answer 12

we can start with one type of triangle like right-triangle and then use tangent ratio and prove

Answer 13

Do you see what I'm saying? Is that process flawed?

Answer 14

ya you can use that or start with that
similar triangles provide congruence

Answer 15

It seems the least convoluted way I've thought.

Answer 16

Could I use the converse(inverse maybe? I forget) of the corresponding angles theorem after saying they're similar to prove parallelism?