Flashcard: Translations & Reflections

Front

What is a translation in geometry?

Back

A translation is a transformation that moves every point of a shape the same distance in a specified direction.

Front

What is a reflection in geometry?

Back

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

Front

What is the line of reflection?

Back

The line of reflection is the line over which a shape is reflected to create its mirror image.

Front

How do you reflect a point over the y-axis?

Back

To reflect a point (x, y) over the y-axis, change the sign of the x-coordinate to (-x, y).

Front

What happens to the coordinates of a point when it is reflected over the x-axis?

Back

When a point (x, y) is reflected over the x-axis, the y-coordinate changes sign, resulting in (x, -y).

Front

What is the effect of translating a shape 4 units down?

Back

Translating a shape 4 units down means subtracting 4 from the y-coordinates of all points in the shape.

Front

If a point is at (3, 2), what is its reflection over the line x = 1?

Back

The reflection of the point (3, 2) over the line x = 1 is (-1, 2).

Front

What is the formula for reflecting a point (x, y) over the line y = k?

Back

To reflect a point (x, y) over the line y = k, use the formula (x, 2k - y).

Front

What does it mean for a shape to be congruent after a transformation?

Back

A shape is congruent after a transformation if it has the same size and shape as the original, even if its position has changed.

Front

How do you determine the line of reflection for two congruent shapes?

Back

The line of reflection is the perpendicular bisector of the segment connecting corresponding points of the two shapes.