Question

If AB = 1, BD = 4, and DE = 6, what is the length of BC ? 1.5 1.4 1.2 2

Answer 1

For this case, the first thing we must observe is that the triangles are similar.
 We can then use the following relationship:
 $BC / DE = AB / (AB + BD)$
 Clearing the value of BC we have:
 $BC = (AB / (AB + BD)) * (DE)$
 Substituting the values we have:
 $BC = (1 / (1 + 4)) * (6)$
 Rewriting we have:
 $BC = (1/5) * (6) BC = 6/5 BC = 1.2$
 Answer:
 The length of BC is given by:
 BC = 1.2