Reflections across Vertical Lines

ForfatterMrs. Clark

Video: Reflection over a horizontal or vertical line

Properties of Reflections

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

Sæt kryds ved dit svar

A
Points reflected across a line are equidistant from the line of reflection.
B
Reflections create congruent figures.
C
The pre-image and image of a reflection face the same direction.

Tjek mine svar (3)

Horizontal or Vertical Lines

Is the graph of y = 4 horizontal or vertical?

Sæt kryds ved dit svar

A
horizontal
B
vertical

Tjek mine svar (3)

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

Question 2

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

Question 3

Reflect Triangle ABC over the line y = -1. Triangle ABC is located at A(-2, 2) B(1, 1) C(3, 5) 1) Graph the vertical line y = -1 using the line tool. 2) Plot the triangle using the polygon tool 3) Use the "reflect about line" tool to reflect the triangle 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 horizontal line (y = #) ? Are there any similarities to reflecting over the x-axis (the x-axis is a horizontal line)?