Triangle [tex][tex]$XYZ$[/tex][/tex] has vertices [tex][tex]$X(1,3), Y(0,0)$[/tex][/tex], and [tex][tex]$Z(-1,2)$[/tex][/tex]. The image of triangle [tex][tex]$XYZ$[/tex][/tex] after a rotation has vertices [tex][tex]$X^{\prime}(-3,1), Y^{\prime}(0,0)$[/tex][/tex], and [tex][tex]$Z^{\prime}(-2,-1)$[/tex][/tex].

Which rule describes the transformation?

A. [tex][tex]$R_{0,90^{\circ}}$[/tex][/tex]
B. [tex][tex]$R_{0,180^{\circ}}$[/tex][/tex]
C. [tex][tex]$R_{0,270^{\circ}}$[/tex][/tex]
D. [tex][tex]$R_{0,360^{\circ}}$[/tex][/tex]



Answer :

To determine which rotation transformation has been applied to triangle [tex]\( XYZ \)[/tex] resulting in [tex]\( X'Y'Z' \)[/tex], we'll analyze the coordinates of the vertices before and after the rotation.

Initial vertices of triangle [tex]\( XYZ \)[/tex]:
- [tex]\( X = (1, 3) \)[/tex]
- [tex]\( Y = (0, 0) \)[/tex]
- [tex]\( Z = (-1, 2) \)[/tex]

Vertices of the image triangle [tex]\( X'Y'Z' \)[/tex] after the rotation:
- [tex]\( X' = (-3, 1) \)[/tex]
- [tex]\( Y' = (0, 0) \)[/tex]
- [tex]\( Z' = (-2, -1) \)[/tex]

We need to check the coordinates of the vertices after applying different rotation transformations around the origin.

### 1. Rotation by [tex]\( 90^\circ \)[/tex] Counterclockwise ([tex]\( R_{0,90^\circ} \)[/tex])
The rule for rotating a point [tex]\((x, y)\)[/tex] by [tex]\( 90^\circ \)[/tex] counterclockwise around the origin is [tex]\((x, y) \to (-y, x)\)[/tex]:

- For [tex]\( X(1, 3) \)[/tex]:
[tex]\[ X \to (-3, 1) \][/tex]

- For [tex]\( Y(0, 0) \)[/tex]:
[tex]\[ Y \to (0, 0) \][/tex]

- For [tex]\( Z(-1, 2) \)[/tex]:
[tex]\[ Z \to (-2, -1) \][/tex]

These calculated points match exactly with the given vertices of [tex]\( X'Y'Z' \)[/tex]:
- [tex]\( X' = (-3, 1) \)[/tex]
- [tex]\( Y' = (0, 0) \)[/tex]
- [tex]\( Z' = (-2, -1) \)[/tex]

Thus, the rotation rule that describes the transformation from [tex]\( XYZ \)[/tex] to [tex]\( X'Y'Z' \)[/tex] is [tex]\( R_{0, 90^\circ} \)[/tex].

Therefore, the correct rule is:
[tex]\[ \boxed{R_{0,90^{\circ}}} \][/tex]

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