Geometry: Reflections

Front

What is a reflection in geometry?

Back

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

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What is the line of reflection?

Back

The line of reflection is the line over which a figure is reflected. It can be the x-axis, y-axis, or any other line.

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

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

Back

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

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

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

Back

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

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What is the rule for reflecting a point across the line y = k?

Back

To reflect a point (x, y) across the line y = k, the new y-coordinate is 2k - y, while the x-coordinate remains the same.

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What is the rule for reflecting a point across the line x = k?

Back

To reflect a point (x, y) across the line x = k, the new x-coordinate is 2k - x, while the y-coordinate remains the same.

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What is the coordinate of A' if A(3, 2) is reflected through the y-axis?

Back

A' is (-3, 2).

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What is the coordinate of B' if B(4, -5) is reflected through the x-axis?

Back

B' is (4, 5).

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What happens to the coordinates of a point when it is reflected through the origin?

Back

When a point (x, y) is reflected through the origin, the new coordinates are (-x, -y).

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What is the vertical axis in a coordinate plane?

Back

The vertical axis in a coordinate plane is the y-axis.

Tags

CCSS.5.G.A.1