Answer:
C.Vertical angles prove that angle 3= angle 6
D.The triangles are similar because alternate interior angles are congruent.
Explanation:
When line d is parallel to line c.
We have to find the true statements about the figure.
Then,
(Vertical angles are equal)


Reason: Alternate interior angles
Two triangles are similar by AA postulate
Reason:Alternate interior angle are congruent.
Option C and D are true.
C.Vertical angles prove that angle 3= angle 6
D.The triangles are similar because alternate interior angles are congruent.