1. What must be true in order for triangles DEF and ABC to be similar? Be very specific about the properties of the angles and sides of these two triangles.
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F
A
B
D
E

Answer/Step-by-step explanation:

For ∆ABC and ∆DEF to be similar the following must be true:

1. ∠A ≅ ∠D

2. ∠B ≅ ∠E

3. ∠C ≅ ∠F

4. The ratio of the length of their corresponding sides must be equal and proportional.

That is:

If all these are true, then ∆ABC ~ ∆DEF, because the corresponding angles of two similar shapes are equal, while the ratio of their corresponding side lengths are equal.

idk

step-by-step explanation:

b. 2 and 4

step-by-step explanation: