Answer:
The length of BC is
![3.6\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/n9loe6jxq3r2sgqz0ilneeq4c7vc0h2pa2.png)
Explanation:
we know that
Triangles ABC and ADE are similar by AAA Theorem
If two figures are similar, then the ratio of its corresponding sides is equal and its corresponding angles are congruent
In this problem
![(AB)/(AD)=(BC)/(DE)](https://img.qammunity.org/2020/formulas/mathematics/high-school/5ok6t1lah2ly883jkjb2q4pq081aen8g0t.png)
substitute the values and solve for BC
![(3)/(5)=(BC)/(6)](https://img.qammunity.org/2020/formulas/mathematics/high-school/cxmmgyben1v0toh4pwg76exvmxjvqpyh74.png)
![BC=6*3/5=3.6\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/q4xh98btp0pel29qaxwjvlgjtkh29bgzsw.png)