Reflections across Horizontal Lines

Video: Reflection over a horizontal or vertical line

Properties of Reflections

Which statements about reflections are true?[br]Select all that apply.

The pre-image and image of a reflection face the same direction. Reflections create congruent figures. Points reflected across a line are [b]equidistant[/b] from the line of reflection.

Horizontal or Vertical Lines

Is the graph of x = 4 horizontal or vertical?

horizontal vertical

Use the graph below to answer the questions that follow.

You can use the graph multiple times for different questions - just delete the previous shapes or images.

Question 1

Reflect the point A(2, 3) over the line x = 2.[br]1) Graph the vertical line x = 2 using the line tool. [br]2) Plot the point (2, 3)[br]3) Use the "reflect about line" tool to reflect the point[br][br]What is the location of the point A' ?

Question 2

Reflect the point A(2, 3) over the line x = -4.[br]1) Graph the vertical line x = -4 using the line tool. [br]2) Plot the point (2, 3)[br]3) Use the "reflect about line" tool to reflect the point[br][br]What is the location of the point A' ?

Question 3

Reflect Triangle ABC over the line x = -1.[br]Triangle ABC is located at A(-2, 2) B(1, 1) C(3, 5)[br]1) Graph the vertical line x = -1 using the line tool. [br]2) Plot the triangle using the polygon tool[br]3) Use the "reflect about line" tool to reflect the triangle[br][br]What are the coordinates of A'B'C'?

Question 4

Based on the previous problems, what observations do you have about reflecting points across any vertical line (x = #) ? Are there any similarities to reflecting over the y-axis (the y-axis is a vertical line)?