Solution
Step 1:
Write the coordinates of the vertices of the original image.
T(-4, 0) , U(-9, -9) , S(-4, -8)
Step 2:
When rotating a point 90 degrees counterclockwise about the origin our point A(x,y) becomes A'(-y,x). In other words, switch x and y and make y negative.
Step 3
Coordinate of the image
T'(0, -4) , U'(9, -9) , S'(8, -4)
Final answer
T'(0, -4) , U'(9, -9) , S'(8, -4)
