Which term describes a transformation that changes the size of an object, but not the shape?

Which term describes a transformation that changes the size of an object, but not the shape?

• A. Dilation
• B. Rotation
• C. Translation
• D. Reflection

Answer: (A)

Changing the size of an object while keeping its shape is called dilation. In a dilation, every point moves along a line from a fixed center by the same factor, so the figure grows or shrinks but angles and overall proportions stay the same. That means the shape remains unchanged, just scaled up or down. In contrast, rotation, translation, and reflection move or flip the figure without changing its size, so they don’t produce a larger or smaller version. For example, enlarging a triangle by a factor of 2 about a center makes its sides twice as long but keeps the angles the same.

Changing the size of an object while keeping its shape is called dilation. In a dilation, every point moves along a line from a fixed center by the same factor, so the figure grows or shrinks but angles and overall proportions stay the same. That means the shape remains unchanged, just scaled up or down. In contrast, rotation, translation, and reflection move or flip the figure without changing its size, so they don’t produce a larger or smaller version. For example, enlarging a triangle by a factor of 2 about a center makes its sides twice as long but keeps the angles the same.