Question

triangle def is congruent to δdef by the sss theorem. which single rigid transformation is required to map δ def onto δdef?
options:
○ dilation
○ reflection
○ rotation
○ translation

Explanation:

1. First, recall the definitions of rigid transformations:

• Dilation is not a rigid transformation as it changes the size (scales the figure), so we can eliminate dilation.
• Reflection is a flip over a line, translation is a slide (moving without rotation or reflection), and rotation is a turn around a point.

1. Looking at the triangles \( \triangle DEF \) and \( \triangle D'EF' \), we can see that the triangles can be mapped onto each other by rotating around point \( E \). The corresponding sides and angles suggest a rotational movement around a common vertex ( \( E \) here) rather than a reflection (which would require a line of symmetry) or translation (which would be a parallel shift).

Answer:

C. rotation