Geometry

Question Analysis:
Tests recognition of transformations that preserve congruence.

Key Concept Explanation:
Only isometries preserve both lengths (distances) and angle measures. Non-isometries alter one or both.

Step-by-Step Solution:
A. Rotation: turns figure, congruence preserved ✅
B. Dilation: changes size ❌
C. Shear / D. Stretch: distort shape and angles ❌

Option Analysis:
Only A keeps both distance and angle measur...