Question

triangle abc is similar to triangle def.
ef = __ in.
(options: 4, 7, 2)
(diagram: triangle abc with ab =? in, bc = 4 in, ac = 5 in; triangle def with de = 3.5 in, ef =?, df =? )

Explanation:

Step1: Find similarity ratio

$\text{Ratio} = \frac{DE}{AB} = \frac{3.5}{7} = 0.5$

Step2: Calculate length of EF

$EF = BC \times \text{Ratio} = 4 \times 0.5$

Answer:

2