Geometry

Question Analysis:
This question involves recognizing transformations that preserve distance.
The main focus is on understanding which transformations qualify as isometries.

Key Concept Explanation:
An isometry is a transformation that preserves distances between points. In other words, the pre-image and the image remain congruent.
The main types of isometries include:
Translation (shifts the figure without rotation or resizing)
Reflection (flips the figure over a line)
Rotation (turns the figure about a fixed point)
Dilations and stretches are NOT isometries because they change the size of the figure.

Step-by-Step Solution:
Analyze each answer choice:
A) Dilation: Changes size, so NOT an isometry.
B) Reflection: Maintains distances, so it IS an isometry. ✅
C) Stretch: Alters proportions, so NOT an isometry.
D) Horizontal compression: Changes the width, so NOT an isometry.
Since a reflection preserves all distances, it is the correct answer.

Common Mistakes:
Confusing di...