1. To get the traingle DEC from the triangle ABC you use the next transformations:
A reflection over the y-axis
A dilatation
2. Reflection: The points in the traingle ABC become in points A'B'C following the next rule
[tex]ABC(x,y)\rightarrow A^{\prime}B^{\prime}C^{\prime}(-x,y)[/tex]
Dilatation: The traingle A'B'C is dilated to get DECfollowing the next rule:
(As you can see the triangle ABC is half size of the triangle DEC, then the scale factor is: 2:1)
[tex]A^{\prime}B^{\prime}C(x,y)\rightarrow DEC(2x,2y)[/tex]
3. The triangles ABC and DEC are similar, as their corresponding sides are proportional but not the same.
(congruent triangles have the same measure in their corresponding sides)
