1. **Problem:** Rotate the triangle with vertices at (2,2), (3,5), (4,2) 90° counterclockwise about the origin. 2. **Formula for 90° counterclockwise rotation:** $$ (x,y) \to (-y,x) $$ This means each point's x-coordinate becomes the negative of its original y-coordinate, and the y-coordinate becomes the original x-coordinate. 3. **Apply the formula to each vertex:** - For (2,2): $$ (2,2) \to (-2,2) $$ - For (3,5): $$ (3,5) \to (-5,3) $$ - For (4,2): $$ (4,2) \to (-2,4) $$ 4. **Result:** The rotated triangle has vertices at $$ (-2,2), (-5,3), (-2,4) $$. This completes the first problem as requested.