Question

Triangle ABC is shown below: Triangle ABC is shown. A is at 2, 1. B is at negative 1, 4. C is at 3, 7. If triangle ABC is reflected over the x-axis, which of the following shows the coordinates for point B'?

Answer 1

B'( -1 , -4).

Explanation:

Given : Triangle ABC is shown. A is at 2, 1. B is at negative 1, 4. C is at 3, 7. If triangle ABC is reflected over the x-axis,

To find : which of the following shows the coordinates for point B'.

Solution : We have given A (2,1 )

B ( -1,4)

C(3,7)

If it is reflected over x axis then,

By the reflection over x axis rule (x , y) →→→→( x , -y).

Then , B(-1 , 4) →→→→ B'( -1 , -4).

Therefore, B'( -1 , -4).

Answer 2

Coordinates of point B':

B' = (-1, -4)

Explanation

To reflect a point or a figure across the x-axis we use the rule:

`(x,y)`→
`(x,-y)`

In other words, we multiply the y-coordinate of our points by -1, while leaving the original x-coordinate as it is.

Let's apply the rule to every point of our triangle :

A = (2, 1)

A' = (2, 1*-1) = (2, -1)

B = (-1, 4)

B' = (-1, 4*-1) = (-1, -4)

C = (3, 7)

C' = (3, 7*-1) = (3, -7)