CPM Homework Help : CCG Problem 5-92

In the diagram below, $ΔABC$ and $ΔADE$ are similar. If $\overline{AB}=5$ , $\overline{BD}=4$ , and $\overline{BC}=7$ , then what is $\overline{DE}$ ? Homework Help ✎

triangle

Hint:

Separate the triangles into two similar triangles.

More Help:

What is the length of $\overline{AD}$ ? Once you know this, since the triangles are similar, the ratios of corresponding sides are equal.
Remember to set up proportions.

Answer:

$\overline{DE}=12.6$ units