If triangle ABC is similar to triangle DFE, then,

∠B = ∠F.

This is because, if triangle abc and trianlge dfe are similar then, corresponding angles are equal. So, ∠B of triangle ABC is equal to ∠F of triangle DFE.

When two triangles are similar, it means that their corresponding angles are equal and the lengths of their corresponding sides are proportional. In this case, the problem states that triangle ABC is similar to triangle DFE. Let’s break it down step by step.

Key Concept: Similar Triangles

Two triangles are said to be similar if:

1. Their corresponding angles are equal.
2. The lengths of their corresponding sides are proportional (though we don't need the side lengths to answer this particular question).

Understanding the Angles

• If triangle ABC is similar to triangle DFE, then:
  • The corresponding angles of the triangles will be equal.
  • Specifically:
    • ∠A of triangle ABC corresponds to ∠D of triangle DFE.
    • ∠B of triangle ABC corresponds to ∠F of triangle DFE.
    • ∠C of triangle ABC corresponds to ∠E of triangle DFE.