CPM Homework Help : CCG Problem 8-129

Multiple Choice: The diagram at right is not drawn to scale. If $\Delta ABC \sim \Delta KLM$ , find $KM$ .

$12$

$15$

$21$

None of these

Two triangles. First is triangle A, B, C with side lengths 6 on side B, C and 9 on side A, C. Second is triangle K, L, M with side lengths 9 on side K, L and 18 on side L, M.

Hint:

The ratios of corresponding sides are equal if two triangles are similar.

More help:

The ratio of corresponding sides is equal to $3$ .