Question

Triangle LMN has been dilated to form triangle L'M'N'. What is the least amount of information needed to determine if the two triangles are similar?

Segments LN and L'N' are congruent, and segments MN and M'N' are congruent.
Angles M and M' are congruent, and angles N and N' are congruent.
Segment BC=B'C', segment LN=L'N', and angles M and M' are congruent.
Angle N=N', angle B=B', and segments BC and B'C' are congruent.

Answer 1

I know this has something to do with the Angle-Angle Postulate, at least I think...
but I'm not sure which answer it would be.

Answer 2

the triangles can be similar by:
1) 2 angles
2) if three sides of 1 triangle are proportional to the three sides of second one
3) if two sides of one triangle are proportional to the two sides of second and angles between them are congruent

Answer 3

I was thinking it would be the last one based on the AA Postulate... would that be right?

Answer 4

i thought B because the segments don't need to be congruent - you already have two congruent angles in last choice, so you don't need segmens at all.

Answer 5

But based on one of the things you said, C sounds right too.

Answer 6

why?



angle M (M') are not between sides BC (BC') and LN (LN')

Answer 7

actually I don't see sides BC at all in these triangles

Answer 8

Well M is between L and N though.
But I see what you're saying. I guess this is just a confusing question for me.

Okay, so it's NOT C or D.
Why couldn't A be right? Just ruling them all out.

Answer 9

you see, they ask the least information, but segments may and may not be congruent - they just need to be proportional. they can be congruent also. and besides there aren't angles. there should have been N=N'

Answer 10

the angles MUST be here, but sides don't have to be congruent

Answer 11

Okay. So any answer that didn't include angles would automatically be wrong?

Answer 12

no. if one triangle has 3 sides proporional to the 3 sides of another, they are also similar

Answer 13

so here they are (all 3 rules)

1)


2)


3)