Given coordinates of the triangle: J(-4,1), K(-4,-2) and L(-3,-1).
We are given that image is rotated 90° counterclockwise about the origin.
In order to find the new coordinates of rotation 90°counterclockwise about the origin, we can apply rule (h, k) ---> (-k,h).
Where (h,k) are the coordinates of original image on axes and (-k,h) are the coordinates of rotated image.
In resulting coordinates of the image first swap the x and y coordinates of the original image and then make the sign opposite of each x-coordinate.
On applying rule (h, k) ---> (-k,h), we get
J(-4,1) --> J'(-1,-4).
K(-4,-2) --> K'(2,-4).
L(-3,-1). --> L'(1,-3).
Blue image is rotation of 90°counterclockwise about the origin.
2) Rule for reflection about y-axis would be (h, k) ---> (-h,k).
On applying rule (h, k) ---> (-h,k), we get
J(-4,1) --> J'(4,1)
K(-4,-2) --> K'(4,-2).
L(-3,-1). --> L'(3,-1).
Red image is reflection across the y-axis.