PDF

Given that triangles LMN and ABC are similar, their corresponding sides are proportional.

Corresponding vertices correspond to corresponding sides, so:

  • LM corresponds to AB
  • MN corresponds to BC
  • LN corresponds to AC

We are given:

  • MN = 15 cm
  • AB = 6 cm
  • BC = 9 cm

Since LMN ∼ ABC, the ratio of corresponding sides is constant. Let's denote the scale factor from triangle ABC to triangle LMN as k.

Since MN corresponds to BC, we can find k as:

k = MN / BC = 15 cm / 9 cm = 5/3

Now, to find LM, which corresponds to AB:

LM = k × AB = (5/3) × 6 cm = 10 cm

Similarly, to find AC (which corresponds to LN):

AC = length in triangle ABC corresponding to LN (this is what the question asks for).

We need to find AC using the known lengths of triangle ABC:

Given AB = 6 cm, BC = 9 cm, and the triangle shape is not stated explicitly, but since it's a triangle, AC is the side in triangle ABC corresponding to LN in LMN.

But from the question, since we know the scale factor k and LN corresponds to AC, we can express LN = k × AC.

If LN is given, we can find AC by dividing by k, but the question only asks for AC's length, so it must be known or can be found by other means.

Since only AB, BC and MN are given, and it's specified we need to find AC, it must be given or can be calculated in triangle ABC using the Law of Cosines if angles or other sides are known. However, no angle measures are provided, so perhaps AC is unknown and needs to be found.

Alternatively, the question may be requesting to find AC assuming the triangles have the same side proportions. So to find AC, we need LN in LMN to scale down by k.

If LN is available in LMN triangle, AC = LN / k.

But since LN is not given, it is not possible to find AC directly without further information.

Summary:

  • Scale factor k = 5/3
  • Length LM = 10 cm
  • Length AC cannot be determined with the given information.

Ask a followup question

Loading...