Lesson 4.1-4.3 Quick Flashcard

Front

What are the coordinates of a point after a 180° rotation about the origin?

Back

To find the coordinates after a 180° rotation about the origin, negate both the x and y coordinates. For example, the point (x, y) becomes (-x, -y).

Front

What is a reflection in geometry?

Back

A reflection is a transformation that flips a figure over a line, creating a mirror image. The line is called the line of reflection.

Front

How do you reflect a point across the x-axis?

Back

To reflect a point (x, y) across the x-axis, the new coordinates will be (x, -y).

Front

What is line symmetry?

Back

Line symmetry occurs when a figure can be divided into two identical halves that are mirror images of each other along a line.

Front

How many lines of symmetry does a square have?

Back

A square has 4 lines of symmetry.

Front

What is a vector translation in geometry?

Back

A vector translation moves every point of a figure the same distance in a specified direction, represented by a vector.

Front

What is the result of reflecting the point (3, 5) in the y-axis?

Back

The coordinates after reflection in the y-axis will be (-3, 5).

Front

What happens to the coordinates of a point when it is rotated 90° counterclockwise?

Back

When a point (x, y) is rotated 90° counterclockwise, the new coordinates become (-y, x).

Front

What is the transformation from point A to point A' if A(2, 3) becomes A'(-3, 2)?

Back

The transformation is a 90° clockwise rotation.

Front

How do you determine the number of lines of symmetry in a regular polygon?

Back

A regular polygon has as many lines of symmetry as it has sides.