Select the correct answer.

A triangle [tex]$\triangle ABC$[/tex] with vertices [tex]$A(-3,0)$[/tex], [tex]$B(-2,3)$[/tex], and [tex]$C(-1,1)$[/tex] is rotated [tex]$180^{\circ}$[/tex] clockwise about the origin. It is then reflected across the line [tex]$y=-x$[/tex]. What are the coordinates of the vertices of the image?

A. [tex]$A^{\prime}(0,3)$[/tex], [tex]$B^{\prime}(2,3)$[/tex], [tex]$C^{\prime}(1,1)$[/tex]
B. [tex]$A^{\prime}(0,-3)$[/tex], [tex]$B^{\prime}(3,-2)$[/tex], [tex]$C^{\prime}(1,-1)$[/tex]
C. [tex]$A^{\prime}(-3,0)$[/tex], [tex]$B^{\prime}(-3,2)$[/tex], [tex]$C^{\prime}(-1,1)$[/tex]
D. [tex]$A^{\prime}(0,-3)$[/tex], [tex]$B^{\prime}(-2,-3)$[/tex], [tex]$C^{\prime}(-1,-1)$[/tex]



Answer :

To solve this problem, we need to determine the coordinates of the image of the triangle [tex]$\triangle ABC$[/tex] after performing two transformations: a [tex]$180^{\circ}$[/tex] clockwise rotation about the origin and a reflection across the line [tex]$y=-x$[/tex]. Let's go through each step in detail:

### Step 1: Rotating [tex]$180^{\circ}$[/tex] clockwise about the origin
When a point [tex]$(x, y)$[/tex] is rotated [tex]$180^{\circ}$[/tex] clockwise about the origin, the new coordinates become [tex]$(-x, -y)$[/tex].

The original coordinates of the vertices are:
- [tex]\( A(-3, 0) \)[/tex]
- [tex]\( B(-2, 3) \)[/tex]
- [tex]\( C(-1, 1) \)[/tex]

Applying the [tex]$180^{\circ}$[/tex] clockwise rotation:
- For vertex [tex]\( A \)[/tex]:
[tex]\[ A' = (-(-3), -(0)) = (3, 0) \][/tex]
- For vertex [tex]\( B \)[/tex]:
[tex]\[ B' = (-(-2), -(3)) = (2, -3) \][/tex]
- For vertex [tex]\( C \)[/tex]:
[tex]\[ C' = (-(-1), -(1)) = (1, -1) \][/tex]

After the [tex]$180^{\circ}$[/tex] rotation, the coordinates of the vertices are:
- [tex]\( A'(3, 0) \)[/tex]
- [tex]\( B'(2, -3) \)[/tex]
- [tex]\( C'(1, -1) \)[/tex]

### Step 2: Reflecting across the line [tex]$y = -x$[/tex]
When a point [tex]$(x, y)$[/tex] is reflected across the line [tex]$y = -x$[/tex], the new coordinates become [tex]$(y, x)$[/tex].

Using the new coordinates from the rotation step:
- For vertex [tex]\( A' \)[/tex]:
[tex]\[ A'' = (0, 3) \][/tex]
- For vertex [tex]\( B' \)[/tex]:
[tex]\[ B'' = (-3, 2) \][/tex]
- For vertex [tex]\( C' \)[/tex]:
[tex]\[ C'' = (-1, 1) \][/tex]

After reflecting across the line [tex]$y = -x$[/tex], the coordinates of the vertices are:
- [tex]\( A''(0, 3) \)[/tex]
- [tex]\( B''(-3, 2) \)[/tex]
- [tex]\( C''(-1, 1) \)[/tex]

Thus, the correct answer is:
### A. [tex]\( A''(0, 3), B''(-3, 2), C''(-1, 1) \)[/tex]

Other Questions