Transformations and Dilations Review

Front

What is a reflection in geometry?

Back

A reflection is a transformation that flips a figure over a line, creating a mirror image.

Front

What is the line of reflection for the point ( -2,5) to (4,5)?

Back

The line of reflection is x = 1.

Front

Define rotational symmetry.

Back

Rotational symmetry is when a figure can be rotated around a center point and still look the same at certain angles.

Front

What is the angle of rotational symmetry for a regular pentagon?

Back

Every 72°.

Front

How do you rotate a point 90° counterclockwise around another point?

Back

Subtract the coordinates of the center point from the point, apply the rotation formula, then add the center point's coordinates back.

Front

What is the image of the point (2, 5) rotated 90° CCW around (1, 3)?

Back

The image is (-1, 4).

Front

What is a dilation in geometry?

Back

A dilation is a transformation that changes the size of a figure but not its shape, using a scale factor.

Front

What happens to the lengths of sides in a dilation with a scale factor k > 1?

Back

The lengths of the sides increase.

Front

If a dilation has a scale factor k < 1, what happens to the angles?

Back

The angles remain the same; only the size changes.

Front

What are the coordinates of the point (a, b) after reflecting over the y-axis and then the x-axis?

Back

The coordinates become (-a, -b).