Question

Triangle ABC has vertices (1,4), (5,6), and (3, 10). It is reflected across the y-axis, forming Triangle A’B’C’. What are the vertices of the new triangle?

Answer 1

Step 1:

First, write the rule for the transformation across the y-axis

The rule for a reflection over the y -axis is (x,y)→(−x,y).

Meaning value of y remains the same and you will multiply the coordinate of x by negative.

Step 2

Coordinates of pre-image

A = (1 , 4)

B = (5 , 6)

C = (3 , 10)

Step 3:

Find the coordinates of the image using the rule.

A' = (-1, 4)

B' = (-5 , 6)

C' = (-3 , 10)

Final answer

The vertices of the new triangle is

A' = (-1, 4)

B' = (-5 , 6)

C' = (-3 , 10)