Question

Right triangle ABC is reflected over AC, then dilated by a scale factor of Two-thirds to form triangle DEC. Which statements about the two triangles must be true? Select three options. △ABC ~ △DEC ∠B ≅ ∠E 3BC = 2EC 3DE = 2AB 3m∠A = 2m∠D 2m∠A = 3m∠D

Answer 1

Answer:

1

2

3

Step-by-step explanation:

Answer 2

Answer:

$\triangle ABC\sim \triangle DEC\\ \\\angle B\cong \angle E\\ \\3BC=2EC$

Step-by-step explanation:

Right triangle ABC is reflected over AC to form triangle AFC.

Triangle AFC dilated by a scale factor of two-thirds to form triangle DEC.

Reflection is a rigid transformation which preserves lengths and angles, then

$\triangle ABC\cong \triangle AFC$

Dilation is a transformation which maps the triangle into similar triangle, so

$\triangle AFC \sim \triangle DEC$

Thus,

$\triangle ABC \sim \triangle DEC$

Similar triangle have congruent corresponding angles, so

$\angle B\cong \angle E$

and proportional corresponding sides

$\dfrac{BC}{EC}=\dfrac{AB}{DE}=\dfrac{2}{3}\Rightarrow \\ \\3BC=2EC\\ \\3AB=2DE$

Thus, correct options are:

$\triangle ABC\sim \triangle DEC\\ \\\angle B\cong \angle E\\ \\3BC=2EC$